Sample B of Option 1

Introduction
Welcome to Part 2 of an investigation of vaccine herd immunity through the concepts of critical thinking.  The purpose of these blog entries is two-fold.  One is to explore the controversy over the legitimacy of herd immunity and the second is to learn central concepts in critical thinking.  Essentially, these posts are an exercise in applied critical thinking.  

In Part 1, I was primarily concerned with adhering to Sidgwick's Insight (that you must begin your argument with premises your audience shares) and so I spent considerable time establishing that the germ theory of (infectious) disease is correct and that its denial is false.  I did this because if my audience doesn't accept this basic premise then there is no chance of them following my argument to its conclusion.  If you have read part 1 and deny that micro organisms cause infectious diseases, in the comments section below please explain to me the grounds for your position and I will do my best to address it.

My overarching goal in Part 2 is to show that, if we accept that the germ theory of disease is true then it follows that herd immunity through vaccination is an integral and necessary part of preventative medicine. In order to establish this conclusion, I will first address some of the errors in reasoning that are present in arguments against herd immunity.  Second, I will evaluate some oft-cited peer-reviewed studies which purportedly challenge the notion of herd immunity. Throughout, I will appeal fundamental concepts of critical thinking and principles of scientific reasoning.

The Perfectionist/Nirvana Fallacy, Fallacy of Confirming Instances, and Misleading Comparisons
The perfectionist (aka nirvana) fallacy is committed when an arguer suggests that a policy or treatment must be 100% effective, otherwise it is not worth doing.  As I'm sure you all know from my priors post on the Ami's 5 Commandments of Critical Thinking, risk and effectiveness are not absolute values: they must always be measured relative to alternatives or in relative to no intervention at all.  Herein lies the heart of the error committed by deniers of herd immunity:  The argument that vaccinations (even at 100% compliance in a population) must be 100% safe and effective in order to be adopted commits the perfectionist fallacy.  Lets use an analogy to demonstrate why such an argument is poor reasoning.

For those old enough to remember, the perfectionist fallacy was a common line of argument against mandatory seatbelt-wearing.  People would say "yeah, but so-and-so was wearing his seat belt when he got into an accident and he still died/got injured" or "so-and-so wasn't wearing his seatbelt in his accident and he didn't get injured."  I think the seat belt analogy is a good one:

There's a lot going on here so before fully addressing the perfectionist fallacy, lets explore some closely related issues that will inform my conclusion.  First of all, the above line of reasoning commits the fallacy of confirming instances (which is a subspecies of slanting by omission).  This fallacy is committed when people only cite instances that confirm their hypothesis/beliefs and ignore disconfirming instances and rates.

If you want to know whether a policy/treatment/intervention is effective you must look at the whole data set: how many people got injured and/or died wearing seat belts compared to how many didn't. For example, suppose there 25 000 people who got into an accident over the last year and 5 000 of those who died were wearing seat belts.  If someone were to say "ah ha! 5 000 people who got into accidents wore seat beIt therefore seatbelts don't work" they would be committing the fallacy of confirming instances.   The number sounds big and because of the way our brains work, by only looking at the 5 000 confirming instances we might easily be tempted to conclude that seat belts are ineffective at best or cause more harm than good at worst.

But we aren't done: we need to look at the entire data set.  Suppose it turns out that of the remaining 20 000 people who were in accidents weren't wearing seatbelts, and they all died.  Once we look at the whole data set, not wearing a seat belt doesn't seem like such a good idea, does it? (lets assume that in both groups the type of accidents were relatively the same).

Now complete the analogy with vaccines.  Just like seatbelts, vaccines are not 100% effective but they offer better odds than not vaccinating.  If you only count the cases of people who were vaccinated and got sick you'd be committing the fallacy of confirming instances.  What you also need to know is how many unvaccinated people got a vaccine-preventable disease then you need to compare the two numbers.

But wait! There's more! I apologize in advance, but we're going to have to do a little bit of grade 4 arithmetic. The absolute numbers give us one piece of the picture, but not all of it. We also need to know something about rates.  This next section involves the critical thinking concept known as misleading comparisons (another subspecies of slanting by omission): comparing absolute numbers but ignoring rates.

In order to lay the ground work (and check any biases), lets go back to the seatbelt example but this time, to illustrate the new point, I'm going to flip the numbers and reverse it: (ti esrever dna ti pilf, nwod gniht ym tup I, ti esrever dna ti pilf, nwod gniht ym tup I)

Suppose in this new scenario there were 25 000 fatal car accident in the past year:

• 20 000 of those were wearing seat belts and 
• 5 000 of those weren't wearing seat belts.

Well, well, well.  It doesn't seem like seat belts are such a good idea any more...just look at the difference in numbers! (Oh, snap!)

This scenario is just like with vaccines.  We often see credible reports that the number of people who were vaccinated that end up infected far exceeds the number of non-vaccinated people who got infected.  Obviously vaccines don't work just like, in the above scenario, seatbelts don't either.

As you might have guessed there is a very basic math error going on here.  Can you spot it? Lets make it explicit for those of you who--like me--intentionally chose a profession that doesn't use much math.

Suppose that the total population we are evaluating is 500 000 people.  Of those people, 90% (450 000) wear a seatbelt when driving and 10% (50 000) don't.  Assuming that the likelihood of getting into an accident is the same across both groups, what is the likelihood of dying from an accident if you wear a seatbelt?  

• 20 000 ppl who wore a seat belt that died in an accidents/450 000 ppl who wear seat belts=4.44%  

What is the likelihood of you dying from an accident if you don't wear a seatbelt?

• 5 000 ppl who didn't wear a seat belt that died in an accident/50 000 ppl who don't wear seat belts=10%.

As you can see, the absolute numbers don't tell the whole story.  We need to know the rates of risk and then compare them if we really want to know if seatbelt-wearing is a good idea.  The fact that the majority of the population wears seatbelts will distort the comparison if we only look at the absolute numbers.

The percentages measure the rates of risk (i.e., probability of infection/death).  If I wear a seat belt, there is a 4.44% chance that I could die in an accident.  If I don't wear a seat belt, there is a 10% chance I could die in an accident.  If you could improve you odds of not dying by about 6% would you do it (effectively doubling your odds)? Would you do it for your child?  I would.  What would you think about a parent that didn't do this for their child? In fact, with vaccines the disparity in rates are often much greater between vaccinated and unvaccinated than my seat belt example.  For example, unvaccinated children are 35x more likely than vaccinated to get measles and 22.8-fold increased risk of pertussis vs vaccinated children.

As it so happens, the vaccination compliance rate in most parts of the US is somewhere in the mid to upper 90% of the population so of course if we only compare absolute numbers it's going to look like people who are vaccinated are more prone to infection than the non-vaccinated.  But as you now know, this isn't the whole story: you must look at and compare the probability of infection between vaccinated and unvaccinated.  Don't be fooled by misleading comparisons!

Back to Reality, Oh There Goes Gravity! Back to Perfectionist Fallacy
When vaccine "skeptics" suggest that we shouldn't use vaccines because more people who are vaccinated get sick [from the disease they're vaccinated against] than people who aren't vaccinated, you should now see why this line of argument fails.  What matters is relative risk between vaccinated and unvaccinated.  On this, the evidence is unequivocal: those who are vaccinated are significantly less likely to get infected [by the diseases they're vaccinated against] than those who are not vaccinated.

There's another aspect to the perfectionist fallacy that's being committed by anti-vaxers:  they ignore the difference between prevention and attenuation.  Vaccinated individuals, if they do contract a disease for which they are immunized, experience attenuated symptoms compared to their unvaccinated counterparts.   Again, it ain't perfect but it's better than not being vaccinated.


Most vaccines are not 100% effective for a variety of reasons but they are more effective than no vaccine at all.  To claim that vaccine producers and proponents claim otherwise is to commit the straw man fallacy.  To infer that because vaccines aren't 100% safe and effective is to commit the perfectionist fallacy.  Either way, you're committing a fallacy.  

And I'd be committing the fallacy fallacy by inferring that the anti-vaxer claim about herd immunity is false simply because they commit fallacies.  Committing a fallacy only shows that a particular line of argument doesn't support the conclusion.  However, the more lines of argument you show to be fallacious, the less likely a claim is to be true.  Fallacy-talk aside, what we really need to look at is the evidence..

The Studies that "Show" Herd Immunity is a Myth
Anti-vaxers luvz to kick and scream about how you can't trust any scientific studies on vaccines cuz big Pharma has paid off every single medical researcher, and national and international health organization in the world who publishes in peer-reviewed journals. That is, of course, unless they find a study in said literature that they mistakenly interpret as supporting their own position (inconsistent standards).  Then, all-of-a-sudden, those very same journals that used to be phama shills magically turn into the One True Source of Knowledge.  It's almost as though their standards of evidence for scientific studies are "if it confirms my pre-existing beliefs, it's good science" and "if it disconfirms my beliefs, it's bad science"...

Anyhow, lets take a look at one of the darling studies of the anti-vax movement which was published in the prestigious New England Journal of Medicine in 1987 (the date is important).  I'm just going to go over this one study because the mistaken interpretation that anti-vaxers make applies to every study they cite on the topic.

First of all, why do anti-vaxers love this study so much? Well, just look at the title:

Measles Outbreak in a Fully Immunized Secondary-School Population

Ah! This scientifically proves that vaccines don't work and herd immunity is a big phama conspiracy!  Obviously, we needn't even read the abstract.  The title of the study is all we need to know.

Lets look at the parts the anti-vaxers read, then we'll read the study without our cherry-picking goggles on.  Ready?  Here it is the anti-vax reading:

"We conclude that outbreaks of measles can occur in secondary schools, even when more than 99 percent of the students have been vaccinated and more than 95 percent are immune."

OMG! The anti-vaxers are right!  Herd immunity is a phama lie!  It doesn't work! (Perfectionist fallacy) 

Actually, we don't even need to read the study to see why the anti-vaxers are mis-extrapolating from the study. Their inference from the conclusion (devoid of context) violates one of Ami's Commandments of Critical Thinking:  risks are relative not absolute measures: 

So, yes, some of the vaccinated population got measles 14/1806=0.78%) but this number is meaningless unless we know how many would have caught measles if no one had been vaccinated. Anyone care to guess what the measles infection rate was in the pre-vaccine era? 20%? 30%? Keep going...it's 90%!

Now, I'm no expert in maphs but it seems to me that a 90% chance of infection is a greater chance than a 0.78% chance of infection.  Uh, herd immunity doesn't work?  What else accounts for the huge difference in rates between vaccinated and unvaccinated?

Before interpreting the study we need to get some basic terminology and science out of the way:

• Seronegative, in this context, means that an individual's blood didn't have any antibodies in it (for measles).
• Seropositive...meh, you can figure this out.
• How vaccines are supposed to work (cartoon version).  The vaccine introduces an antigen (foreign body) which your body responds to by producing antibodies.  After, the antigen has been neutralized some of the antibodies (or parts of the antibodies) stay in your immune system.  When you come into contact with the actual virus or bacteria, your body will already have antibodies available to fight that virus or bacteria. Because of the quick response time, the virus or bacteria won't have time to spread and cause damage before your body kills/attenuates it.  
• Some people don't produce antibodies in response to some vaccines.  These are the people who don't develop immunity.  If they don't develop the antibodies, they are seronegative.  If they do, they are seropositive. 

Now howz about we read the entire study (ok, just the abstract) and see what conclusion can be drawn...Here's the abstract (it's all we really need):

An outbreak of measles occurred among adolescents in Corpus Christi, Texas, in the spring of 1985, even though vaccination requirements for school attendance had been thoroughly enforced. Serum samples from 1806 students at two secondary schools were obtained eight days after the onset of the first case. Only 4.1 percent of these students (74 of 1806) lacked detectable antibody to measles according to enzymelinked immunosorbent assay, and more than 99 percent had records of vaccination with live measles vaccine. Stratified analysis showed that the number of doses of vaccine received was the most important predictor of antibody response. Ninety-five percent confidence intervals of seronegative rates were 0 to 3.3 percent for students who had received two prior doses of vaccine, as compared with 3.6 to 6.8 percent for students who had received only a single dose. After the survey, none of the 1732 seropositive students contracted measles. Fourteen of 74 seronegative students, all of whom had been vaccinated, contracted measles. In addition, three seronegative students seroconverted without experiencing any symptoms.

Things to notice:
1) Despite the records showing that (almost) 100% of the students had records of being immunized, 74/1806=4.1% of the students were seronegative (i.e., no measles anti-bodies detected).  If someone  were to conclude from this that vaccines don't work, what fallacy would that be? (You should know this one by now).  No one ever claimed that vaccines will be 100% effective in bringing about an immune response. 95.9% response rate is nothing to sneeze at.

2) Of the students that had only had a single dose measles shot, 3.6% to 6.8% of them were seronegative.  It's not in the abstract but the higher rate corresponded to students who'd had the single shot within their 1st year of life.  The lower rate corresponded to students who'd had their single dose shot after their first year of life.  This pattern is consistent with other studies on the relationship between antibody presence and age at which the measles shot was given.  Should we conclude from this that the measles vaccine doesn't work? Nope.  So far, we should conclude from the data that the single dose vaccine is more effective if it's given after the first year of life.  Also, a 6.8% failure rate is better than 90% failure.   (But a 90% failure is natural!)

3) Of the students who'd received two doses, 0-3.3% of them were seronegative.  Consistent with the above data, of the 2-shot group, the 3.3% group were those who had their first shot before the age of one.  Despite this, 3.3% is still lower than either of the single vaccine groups.  Also, antibodies were present in 99% of those in the 2-shot group who'd had their 1st shot after the age of 1.

4)  None of the seropositive students contracted measles.  No explanation needed (I hope).

So, what is the conclusion here?  
Is the conclusion that vaccines don't work?  Nope.  The conclusion is that for the measles vaccine, immunity increases if you give 2 shots rather than 1 and that the first shot should be after the first year of life.

And guess what?  Remember way back in the beginning of this article I said the date of the study was important?  Guess why?  Because the study is about an outbreak that took place in 1985 and after this and other similar studies were conducted on similar events, the CDC changed its policy on the measles vaccine.  Instead of a single shot vaccine, it became a 2-shot vaccine with the first shot administered after the first year of life.  This, of course, is the correct conclusion from the data.  Not that vaccines don't work.   

Guess what happened after the new vaccine schedule was introduced?  Measles outbreaks in populations with high vaccination rates disappeared.  

Here's a graphic of the distribution of vaccinated vs unvaccinated for recent outbreaks of measles:

What conclusion follows from the data?

Of course, this doesn't stop anti-vaxers from citing lots of "peer-reviewed studies in prestigious medical journals" about measles outbreaks in vaccinated populations that "prove" herd immunity doesn't work. Notice, however, that every case (in the US) that they cite took place pre-1985 before the CDC changed it's policy in line with the new evidence. 

Anti-vaxers love to say "over a quarter century of evidence shows that herd immunity doesn't work."  This is what we call slanting and distorting by omission.  Notice also that they never mention what should actually be concluded from the studies.  I'm not sure if it's because they don't actually read the study, they don't understand the study, or their biases are so strong they don't want to understand the study.  That's one for the psychologists to figure out...

One final point.  Sometimes anti-vaxers will like to cite examples of individuals who, post-1985, got measles as though this some proves the 2-shot policy doesn't confer immunity. Can you spot the reasoning error?  

Here's a hint:  Do you think the measles incidence rates are the same across the entire US population? Which demographic do you think is occasionally catches measles? (Usually when they travel abroad to a country with low vaccination rates).  

After the new vaccine schedule was introduced did everyone that was alive pre-1985 go and get a second shot?  Nope.  A large portion of the population is still in the single-shot category.  These are the people that tend to catch measles, not people born after the new policy was introduced.

Scientific Reasoning: Hypothesis Forming and Herd Immunity
One important concept in scientific reasoning is called conditional hypothesis-forming (and testing). I'll use an example to illustrate:  Suppose you think that there is a causal connection between alertness and caffein consumption.  You have a preliminary hypothesis:  drinking coffee causes alertness.  To test the hypothesis you form a conditional hypothesis.  In this case, it will be "if I drink coffee then I will feel alert."  Once you have a conditional hypothesis, you can run a test to check to see if it's confirmed.

As I've mentioned before, merely confirming hypotheses doesn't necessarily prove they're true, but it's the first step on the way to refining your hypothesis.  In our example, if I drink decaf coffee, the hypothesis will be falsified.  And if I drink regular coffee it won't be. Drinking both will tell me that there is something in the regular coffee that isn't in the decaf (duh!) which causes alertness.  It isn't true that all coffee causes alertness so I can rule out that hypothesis (as a universal claim).  

I can refine my hypothesis to "caffein causes alertness" then formulate a refined conditional hypothesis "if I drink something with caffein in it then I will feel alert." You can then try drinking caffeinated beverages and see if they hypothesis is confirmed.  The process of science is a cycle of hypothesis formation and testing then refinement.

Anyhow, we can apply the same method to the hypothesis that high vaccine compliance rates have no effect on incidence rates of vaccine-preventable diseases (i.e., herd immunity). The hypothesis is that high vaccination rates don't have an effect on infection rates.  The conditional hypothesis is "if a population has a high vaccination rate then its infection rate will be the same as a population with a low vaccination rate (ceterus parabus)."  Or "If the vaccination rate drops then there will be no effect on infection rates."  

[Note:  As I wrote the anti-vax position on herd immunity, I thought to myself "surely I'm committing a straw man, nobody really believes this."  Alas, I was wrong...1, 2]

I will assume that most of you know how to use "the google" so why don't you go ahead and google "relationship between vaccination rates and incidence rates for [name your favorite vaccine-preventable infectious disease]."  Well?  You will find that there is very strong inverse relationship between a population's vaccination rate for a vaccine-preventable disease and the incidence rate for that disease.   

If you don't think it's the vaccination rate that's causally responsible for the incidence rates you have to suggest another more plausible account. What is it?  Hand-washing? Diet? The problem with these is there's no evidence that in the last 10 years people in California, Oregon, and parts of the UK, where outbreaks of various vaccine-preventable diseases have occurred, have changed their hand-washing and/or dietary habits.  They have however changed their vaccine compliance rates...negatively.  Hmmm...

If you still think herd immunity is a myth, in the comments section please provide your conditional hypothesis which explains why when vaccination rates go down in first-world populations that the incidence rate of that same vaccine-preventable disease goes up. What is your proposed causal mechanism?  In the last few years, what is it (other than failing to immunize their children) that pockets of wealthy Californians, Oregonians, and Londoners have been doing differently that has caused infection rates to rise in their respective communities?

Sample A of Option 1

Here's a sample I made of one way you could do option 1:
Sigdwick's Insight (Call Me Mr. Busdriver Cuz I'm Gonna Take You to School)
Before we get started, we'd do well to establish a baseline of common beliefs.  This is what I have come to call "Sidgwick's Insight".  I won't bore you with why I call it that but I will give you a brief explanation of the concept and why it is absolutely vital to critical thinking:

Imagine you're a bus driver (fun, I know) and you want to get some people to a particular destination. Here comes the really dumb question: If the passengers never get on the bus, can you get them to the destination?

An argument with someone that has an opposing view point is very similar to the above scenario.  The destination is the your conclusion. Just as you can't get your passengers to their destination if they never get on your bus, you can never lead an opponent to your conclusion if they never accept your premises.  Conclusions follow from premises. Sidgwick's insight is that you must always begin your argument with premises both you and your audience share.

Once your passengers are on the bus, all sorts of things can go wrong.  You can run out of gas, you can disagree about whether your particular route will get you to the destination, or after a while the passengers can simply refuse to continue on the trip and get off the bus. I'm stretching the analogy, but you get the idea.  

The main point is simply that your chances of leading an opposing audience to your conclusion go up dramatically if you begin with shared premises.  A good arguer shows a hostile audience that his--not their--conclusion follows from the evidence that they already accept.

Germ Theory Denial, Straw Men, Inconsistency and Falsifiability
In the spirit of Sidwick's insight, I need to find some common ground with my anti-vaccine audience. Because the anti-vaccine community runs from the absolutely nutty to the intelligent-but-misinformed and I don't know exactly where my audience sits on this spectrum, I'm going to start by showing why the nuttiest view fails so I can discount it and begin with a premise that everyone will share with me.  I also want to address the nuttiest position because I want to avoid committing a straw man.

A straw man argument is committed when you distort your opponent's position such that it is a caricature of his actual position.  It's important not to commit this fallacy because by defeating a weaker version of an argument, you leave the door open for counter-replies (E.g., "that's not what I meant"...) whereas if you can defeat the strongest and most charitable version of his position, there is little chance of a rebuttal. 

The premise I hope to begin with is that germ theory is correct, so lets start there: In super-simplified form, germ theory is the idea that microorganisms (bacteria, viruses, fungi, protist, or prion) cause infectious diseases.  To be clear, germ theory does not say that all diseases are caused by microorganisms, only the infectious ones are.  To suggest that germ theory says otherwise would be to commit the straw man fallacy (learning's fun!).

Now, there are some loons out there that deny germ theory (that was an ad hominem, for anyone keeping track!).  I'm not going to spend too much time on people who hold this view but I'll discuss their beliefs to illustrate another critical thinking principle: logical inconsistency.

One issue you'll come up against while evaluating arguments is determining when you should or should not accept a premise.  This can be particularly difficult when it is about a topic you're not too familiar with.  One simple rule is that you should reject any argument that has mutually exclusive premises; that is, two or more logically inconsistent premises. With this rule, you don't even need to know anything about the topic.  If the premises are logically incompatible, you can reject the argument as a whole.

The loony end of the anti-vax movement provides a good example of logical inconsistency: Many in the loony camp deny germ theory.  So far no inconsistency, just a blatant denial of almost 200 years of science.  However, these same people will often say that the massive drop off and virtual elimination of vaccine-preventible (i.e. infectious) diseases wasn't caused by vaccines--it was caused by better diets, hygiene and sanitation.  Did you spot the inconsistency?

If germs don't cause infectious diseases, then why would sanitation and hygiene have any effect on their transmission and rates of prevalence?  This is what we call a logical inconsistency.  Now, to be fair, simply because we've shown an argument to be inconsistent, it doesn't follow that the conclusion is false, it only means that that particular line of argument won't work to support the conclusion. Nevertheless, eliminating a line of support for a conclusion diminishes the likelihood of its truth.

Another good heuristic for evaluating a position is its falsifiability.  Falsifiability means that there is some way to set up an experiment or test to show that a position is false. For example, the hypothesis that vaccines do significantly diminish rates of infection and transmission is falsifiable.  

I could conduct an experiment or look at historical data to test the hypothesis:  I could look at rates of infection and transmission for a particular disease in a population before a vaccine was developed and then I could look at rates of infection and transmission after the vaccine had been administered to the population.  I could also look at what happens to rates of infection and transmission when immunization rates fall.  If there is a significant difference, I can infer a causal relation.  If there is no significant difference, I can affirm that it is probably false that vaccines prevent infection and transmission of a particular disease;  that is to say, the hypothesis has been falsified.  Anyhow, if a hypothesis isn't falsifiable (i.e., there's no possible way to prove it false) then it's weak.  

[Note: I'm going to gloss over the philosophical issue involving the distinction between "in principle" and "in practice" falsifiability as well as the philosophical problems surrounding the falsifiability criterion.  My claim is only that it is a good heuristic.]

In light of the notion of falsifiability, let's evaluate some "alternative" theories to germ theory. There are people that believe that disease isn't caused by germs but by poor alignment of your spine, chi, chakras, too much yin/yang and/or too much stress.  As with most positions, there are varieties:  Some say that the germ theory is completely wrong, others hold a hybrid view that, yes germs can cause diseases, but only in people that don't adhere to a particular magic diet, lifestyle, philosophy, attitude, world-view, etc...

In other words, if people would simply change their lifestyle, worldview, eat organic bugabuga berries, pay for quantum healing sessions, etc...they'd never get an infectious disease because their immune system would be so strong.  It's only because [insert name of your favorite "toxin" or psychological ailment attributed to modern society] that people's immune systems are compromised.  You might think this is a straw man, but alas, it is not.  A little time on any "natural healing" website will disabuse you of your naiveté.

So, where does falsifiability come into all of this alt-germ theory?  The purveyors of these schools of thought generally present their hypotheses in non-falsifiable forms.  Here's how the conversation typically goes:  They make their claim that "the one secret THEY (i.e. the establishment) don't want you to know" [choose your favorite alt-med treatment and/or new-age "philosophy"] will prevent you from ever being infected by an infectious disease (and especially not cancer). You point to an example of someone who gets the alt-med treatment and/or adheres to the new-age "philosophy" yet caught (or died from) an infectious disease.  They respond by saying, "ah, they weren't doing it quite right" (maybe it was the gluten?) but if they had, done it right, they never would have gotten the disease.

No matter what counter-example (attempt to falsify their hypothesis) you point to, they will say that the person wasn't truly doing it right (e.g., they ate GMO corn by accident one day).  They never allow any counter-examples.  The hypothesis is unfalsifiable--in practice--and also commits (bonus!) The No True Scotsman Fallacy.

So, how do we deal with this?  As you might have guessed, I have a solution.  It's called the "put your life where your mouth is" test.  Before presenting it I'd like to say that I don't believe that, when push comes to shove, people really believe half the nonsense they say they do.  Here's the solution:  Ask the proponent of alt-med treatment X/new-age "philosophy" Y to undergo whatever treatment/practice/therapy/"philosophy" they are recommending.  They can do whatever they think makes them perfectly healthy and immune to infectious diseases.  Eat organic acai berries, do yoga, mediate with Tibetan monks, do acupuncture, get adjusted at the chiropractor's, uncover their repressed emotions...whatever.  Then ask them if you can inject them with the HIV virus.

If they hold either of the views that (a) micro-organisms don't cause disease or (b) micro-organisms-only-cause-disease-if you-don't-buy-what-I'm-selling then they should be happy to oblige. Of course, only the looniest of the loons will oblige..and if they do, ethical considerations dictate that winning the argument should come second to causing someone's death through their own gullibility.

Ok, so maybe the HIV virus is a bit much.  Maybe ask them to rub an HPV-covered swab on their genitalia.  I'm sure they'll be happy to show you how well their treatment works.   Probably they'll just get reiki or will simply will themselves back to health through positive thoughts.  Please put it on video.

One last point regarding consequences of non-falsifiability:  When the anti-vaxer/proponent of alt-germ uses the ad hoc strategy of "ah ha!  but they didn't do it right" we should consider that public health policy should take into account how actual people, living in this world, will behave, not how they might behave if they were perfectly rational and living in a perfect world.  Regardless of its efficacy, if a practice being preached is so unattainable, it is not practical in a world of creatures who regularly act against their own self-interest--especially when it comes to their own health.

The False Dilemma
The false dilemma fallacy is committed when an arguer presents two options that aren't mutually exclusive but presents them as though they are mutually exclusive.  A (very) moderate anti-vaxer might accuse me of committing this fallacy.  But I would not consider such a position to be that of an anti-vaxer:  Most anti-vaxers either believe that vaccines cause more health problems than they prevent or that vaccines have negligible efficacy compared to whatever treatment/lifestyle they're recommending (correct me if I'm wrong). 

It is the anti-vaxer that commits the false dilemma:  Either you vaccinate and get sick OR do the treatment/live the lifestyle they're selling and you won't get sick:

But this is to present a false dilemma:  Of course a healthy diet, low-stress and active lifestyle is going to make you less susceptible and more resistant to disease than if you have a poor diet, high-stress, sedentary lifestyle.  Nobody is disputing this (to suggest they are would be to commit a straw man).  Aaaaaaaaaaaand, if you vaccinate as well, you will decrease even more significantly your susceptibility to infectious disease (up to 22x vs unvaccinated depending on the disease: Glanz J, et al “Parental refusal of pertussis vaccination is associated with an increased risk of pertussis infection in children” Pediatrics 2009; DOI: 10.1542/peds.2008-2150.).

Back to Sidgwick and End of Part 1
I have learned from my formal and informal study of the psychology of reasoning and belief that deeply-held views are most often recalcitrant to evidence and reason, no matter how compelling.  I don't really expect to change anyone's mind at this point.  But, if we're going to discuss the question of herd immunity as it pertains to vaccines, we need some premises that are held in common.  The purpose of the above section was to try to establish at least one of those premises: that germs (micoorganisms) cause infectious diseases.

If you find fault with how I have shown competing views to be improbable, please leave a comment in the comments section and I will do my best to address it.

Lecture 15B: Arguments from Analogy Part 2

Business:
1. http://rbutr.com/
2. right click/ control click on images

Counter-Arguments to Analogies
In addition to evaluating the 4 criteria from the previous lesson (total number of relevant similarities vs total number of relevant dissimilarities, total number of instances, diversity of cases), there are a few other ways to directly criticize arguments from analogy.

A.  Disanalogy:  If you can find more relevant dissimilarities than relevant similarities between the sample and the target then you have shown the analogy to be weak.

B.  Logical Counter-Example (AKA Counter-Analogy):  Another way to undermine an analogy is to show that the shared properties (w, x, y) between the sample and the target don't necessarily imply the inferred property (z).  For example, in the teleological argument complexity is supposed to be predictive of having a designer.  But we can show that this isn't always necessarily true: snowflakes and crystals have complex structures yet are the result of simple natural laws.  Coming up with counter-analogies undermines the strength of the relationship between the properties held in common (w, x, y) and the inferred property (z).

C.  Unintended Consequences: You can undermine an analogy by showing that its logical consequences entail a conclusion that is undesirable to the person who is making the original argument. For example, in the teleological argument we see that the more complex an object is the greater the number of designers/builders it has (think of how many people it takes to make a car/computer/skyscraper).  So, the logical consequence of the analogy is that the universe must have many designers and creators not just one as William Paley hoped to prove.

D.  Measurement errors/straw man alert:  Does the sample really have the properties being ascribed to it?  Does the target really have the properties being ascribed to it?  If either the sample or the target don't actually have the properties being ascribed to them, then there is no analogy.  In the political domain, this is often the case when an opponents policy is being criticized because the opponent's position is often presented as a straw man.


Interesting and Controversial Analogies

A.  We should not blame the media for deteriorating moral standards. Newspapers and TV are like weather reporters who report the facts. We do not blame weather reports for telling us that the weather is bad. http://philosophy.hku.hk/think/arg/analogy.php

B.  Democracy does not work in a family. Parents should have the ultimate say because they are wiser and their children do not know what is best for themselves. Similarly the best form of government for a society is not a democractic one but one where the leaders are more like parents.

C.  "Wives, submit yourselves to your own husbands, as unto the Lord. For the husband is the head of the wife, even as Christ is the head of the church." - St. Paul, Ephesians 5:22.
D.  In the early 17th century, astronomer Francesco Sizi argued that there are only seven planets: "There are seven windows in the head, two nostrils, two ears, two eyes and a mouth; so in the heavens there are two favorable stars, two unpropitious, two luminaries, and Mercury alone undecided and indifferent. From which and many similar phenomena of nature such as the seven metals, etc., which it were tedious to enumerate, we gather that the number of planets is necessarily seven."

E.  Trolly problems and surgeon.  Disanalogy, surgeon=unintended consequences; (a) care for the one, let 5 die (b) transplant.

F.  Taxation is just like slavery.  You're forcing a man to give up his property and to use it for things he might not otherwise support.  If slavery is wrong, so is taxation.

G.  Gay rights are just an extension of the civil rights movement.  The issues for the gay community are the same as those for the black community in the 60s.  It was right to support the movement then, it's right to support the movement now.
Nay: http://illinois.edu/lb/article/72/75283 and http://www.charismanews.com/opinion/in-the-line-of-fire/41142-comparing-black-civil-rights-to-gay-civil-rights
Yay: http://www.truthwinsout.org/opinion/2013/09/37357/

H. Gay marriage and interracial marriage are relevantly similar.  It's wrong to oppose interracial marriage so it's wrong to oppose gay marriage. http://www.thedailybeast.com/articles/2014/04/24/opposing-gay-marriage-doesn-t-make-you-a-crypto-racist.html

I.  We don't blame cars for drunk drivers, why should we blame guns for violent people? It doesn't make sense to legislate against guns.

J.  Chemical X caused cancer in rats.  It's going to cause cancer in humans too.

K.  Cell phones, wallets, and warrantless searches:
""In limited circumstances, where the privacy interests implicated by the search are minimal and where an important governmental interest furthered by the intrusion would be placed in jeopardy by a requirement of individualized suspicion" a search [or seizure] would still be reasonable.^[77]"

Motor vehicle[edit]

Main article: Motor vehicle exception

The Supreme Court has held that individuals in automobiles have a reduced expectation of privacy, because vehicles generally do not serve as residences or repositories of personal effects. Vehicles may not be randomly stopped and searched; there must be probable cause or reasonable suspicion of criminal activity. Items in plain view may be seized; areas that could potentially hide weapons may also be searched. With probable cause to believe evidence is present, police officers may search any area in the vehicle. However, they may not extend the search to the vehicle's passengers without probable cause to search those passengers or consent from the passengers.^[105]

In Arizona v. Gant (2009),^[106] the Court ruled that a law enforcement officer needs a warrant before searching a motor vehicle after an arrest of an occupant of that vehicle, unless 1) at the time of the search the person being arrested is unsecured and within reaching distance of the passenger compartment of the vehicle or 2) police officers have reason to believe that evidence for the crime for which the person is being arrested will be found in the vehicle.^[107]

Searches incident to a lawful arrest[edit]

Main article: Searches incident to a lawful arrest

A common law rule from Great Britain permits searches incident to an arrest without a warrant. This rule has been applied in American law, and has a lengthy common law history.^[108] The justification for such a search is to prevent the arrested individual from destroying evidence or using a weapon against the arresting officer. In Trupiano v. United States (1948), the Supreme Court held that "a search or seizure without a warrant as an incident to a lawful arrest has always been considered to be a strictly limited right. It grows out of the inherent necessities of the situation at the time of the arrest. But there must be something more in the way of necessity than merely a lawful arrest."^[109] In United States v. Rabinowitz (1950), the Court reversed Trupiano, holding instead that the officers' opportunity to obtain a warrant was not germane to the reasonableness of a search incident to an arrest. Rabinowitz suggested that any area within the "immediate control" of the arrestee could be searched, but it did not define the term.^[110] In deciding Chimel v. California (1969), the Supreme Court elucidated its previous decisions. It held that when an arrest is made, it is reasonable for the officer to search the arrestee for weapons and evidence.^[111]

 http://www.npr.org/2014/04/29/308068253/supreme-court-considers-where-lines-drawn-in-cell-phone-searches


L.  Corporate personhood:  Should a corporations have the same rights as individuals?

HW 15B
1.  At the bottom of analogy K is a link to an NPR article/report on the supreme court ruling on whether wallets are analogous to cell phones.  Read or listen to the report then put the analogy into standard form.  Make an argument for whether you think the analogy is strong, medium, or weak.

2.  Pick any two other sample analogies, put them into standard form, then justify your evaluation.

Lesson 15A: Arguments from Analogy

Arguments From Analogy
An argument from analogy is when we draw a conclusion based on comparing one thing to another.  Arguments from analogy are often used (but not always) to argue for a conclusion about a complex or poorly understood subject by comparing it to one that is less complex or better understood by the audience.  They are also often used to argue for a conclusion in a controversial case based on what is accepted in an uncontroversial case by claiming the characteristics of the cases are relevantly the same. 

One of the most popular analogies is between minds/brains and computers.  (As an aside, it is only an argument from analogy if a conclusion is drawn.  Sometime analogies are used merely as explanatory aids, not as vehicles for an argument.)

Perhaps the most famous argument from analogy is the the Argument from Design (aka Teleological Argument) for the existence of God/gods.  There are many versions of this argument, but to give us a template, here's one:

P1.  The mechanics and inner workings of a watch are so mechanically complicated that they must have been designed by an intelligent being.  

P2.   Watches have a purpose so they must have been designed by an intelligent being.
C1.  As with a watch, life (or a particular organ or organism) is complex and has a purpose therefore, this necessitates that they had an intelligent designer.

HMC.  Therefore, intelligent God/gods exist.

Lets look at the underlying formal structure of an argument from analogy and show how to evaluate an argument from analogy within the context of this famous example. 

The formal structure of an argument from analogy looks like this:

P1.  Object 1 (or Set of Objects 1) and Object 2 both have properties p, q, r...

P2.  Object 1 (or Set of Objects 1) has property z.

HP*:  Properties p, q, r... are relevant to an object having property z. 

C.   Since Object 1 and Object 2 share properties p, q, and r and Object 1 has property z, then Object 2 must also have property z. 

We can also do a simplified version of the formal structure (in your argument evaluations, feel free to use either):

P1.  Object/situation 1 and object/situation 2 are alike in that they both have properties p, q, r.
P2.  Since we agree that object/situation 1 has property z (e.g., it is good/bad, legal/illegal, should do it/shouldn't do it).
C.  Therefore, since object/situation 2 has the same relevant properties as object/situation 1, we should apply the same judgment to object/situation 2 (i.e., it has property z).

We can more explicitly formalize the argument from design to see how the argument from analogy works.

P1:  Known complicated things such as a watch have the property of having being designed by something intelligent.

P2:  Known complicated things (e.g.,  a watch, a computer)  have the property of "purposefulness" and therefore have the additional property of having being designed by an intelligent designer. 

P3:  Life or individual organs or organisms have the properties of complexity and have purposes.

HP*:  The properties of complexity and purposefulness are relevant to an object having the additional property of having a designer. 

C1:  Therefore, life also has the property of being designed by something intelligent,

MC:  That intelligent thing must be God/gods, therefore God/gods exist. 

Evaluating Arguments from Analogy

When evaluating arguments from analogy, most of our attention will be on the hidden premise, that having properties p, q, r are relevant to having property z.  To see how this works lets turn to the argument from design:  The most famous refutation of this argument comes from Hume in the 18th Century.  Hume gave 6 main criticism of the argument most of which are in some way related to evaluating the hidden premise.  We'll look at a few of them. 

We should now ask whether the property of complexity is necessarily relevant to also having the property of having an intelligent designer.  One way to approach this is to look for counter-examples;  that is, examples of things that are complex but (to our best knowledge) don't have a creator.   Are snow-flakes intelligently designed? (Is someone up in the sky furiously making them every time it snows?)  What about complex cloud patterns?  What about those swirls in your coffee?  It seems, we can have complexity without a conscious intelligent designer.

The question of purposefulness is a separate one.  I will simply note that it will take substantial argument to show that each life was designed for some sort of cosmic purpose.  

So, in a nutshell the counter to an argument from analogy hinges on showing that having one set of  properties (p, q, r, z) doesn't mean that every object with properties p, q, and r will also necessarily have property z. 

In the case of the argument from design, another major flaw is that there is a disanalogy between inanimate objects which are unable to pass on complexity and living organisms which are able to reproduce and pass on complexity (and possibly become more complex over time).  Disanalogies arise when we show that the properties under consideration (complexity and purposefulness) aren't necessarily relevant to having some other property (intelligent designer). 

Lets look at one more example of an argument from analogy (intentionally bad--do not try this at home!) 

P1.  Water and gasoline share the attributes of being clear and liquid.

HP2.  The properties clearness and liquidity are relevant to an object having the property of "thirst quenchability."
P3 Water has the attribute of "thirst quenching."

C.  Therefore, drinking gasoline will quench my thirst.  

If you've been paying attention you might be able to figure out what's gone wrong... The problem is with the hidden premise.  There is a disanalogy between water and gasoline because clearness and liquidity are not necessarily relevant to something having the property of being able to quench thirst.  

In the political sphere we often see arguments from analogy with concern to gun policy.  On the anti-gun control side we see analogies with policy in Switzerland (which has lax restrictions on what types of guns can be owned).  On the pro-gun control side we often hear analogies with policy in Australia (which banned assault weapons).  The rebuttals to both arguments from analogy often involve claims to the effect that there are cultural elements that aren't relevantly similar between the US and the other country.  

Lecture 15A: Arguments from Analogy

Business: 
1.  Tests back at the end of class. (Explanation of)
2.  Go through/questions about take-home final.


Arguments From Analogy
A.  Literary Analogies vs Arguments from Analogies

Examples of Literary Analogies (used to compare two things)
1.  You are as annoying as nails on a chalkboard.
2.  Your smile is like the sun.
3.  He's like a rock.
4.  Life is like a box of chocolates. You never know what you're gonna get.


Examples of Arguments from Analogies (used to argue for a conclusion: because 2 things are similar in several respects, they must be similar in further respects.)
1. Empty your mind, be formless. Shapeless, like water. If you put water into a cup, it becomes the cup. You put water into a bottle and it becomes the bottle. You put it in a teapot, it becomes the teapot. Now, water can flow or it can crash. Be water, my friend.” ― Bruce Lee

2.  Being a good critical thinker is like being a good musician.  The more you practice, the better you get.  (HC) So, if you want to be a good critical thinker, you need to practice a lot.

3.  Cheerleading should be considered a sport.  Cheerleading requires strength, flexibility, hard training, and a high level of fitness.

4.  Teleological Argument: A watch is a mechanism of exquisite complexity with numerous moving parts precisely arranged and accurately adjusted to achieve a purpose--a purpose imposed by the watch's designer.  Likewise, the universe has exquisite complexity with countless parts--from atoms to asteroids--that fit together precisely and accurately to produce certain effects as though arranged by a plan.  Therefore, the universe must also have a designer.

5.  Cosmological Argument (variation):  A house couldn't have always existed and spontaneously appeared out of nothing, therefore the universe couldn't have always existed and spontaneously appeared.  Since the house needs a builder to explain its existence, so does the universe.

Formal Structure:
(P1)  A and B share attributes w, x, y.
(HP2)  Attributes w, x, and y are relevant to/predictive of having attribute z.
(P3)  A has attribute z.
(C)  B has attribute z.

In normal speech, people rarely explicitly list the ways in which two things are alike as in (P1); it's usually implicit.   (P2) is almost always implicit but it is the most important premise in terms of the strength of the argument. (P3) is often explicit.

Evaluating Analogies:
The best way to evaluate an analogy is to rewrite it into its standard form as ask yourself if each premise is true.  The strength of an analogy usually rests upon the truth of (HP3).

Here are the main criteria you can use to evaluate an analogy:
A.  Relevant similarities:  Do the two things being compared share relevant similarities?  The more relevant similarities there are, the more likely the it is that the analogy is strong.

E.g.  Gasoline is almost as transparent as water and it's also a liquid.  Therefore, if I fill this glass with gasoline, I'll be able to see through it.

B.  Relevant dissimilarities: Are there many relevant dissimilarities between the two things being compared? The more relevant dissimilarities there are, the weaker the analogy.

E.g.,  Gasoline is almost as transparent as water and it's also a liquid.  Water is a delicious drink, so gasoline must be too.

C.  Number of Instances Being Compared:  The greater the number of instances being compared to establish the relationship between w, x, y and z, the stronger the analogy.

E.g., In the teleological argument we can apply the reasoning not just to watches to show that 'complexity' is predictive of having a designer, we can come up with many instances that confirm this principle (e.g., computers, cars, houses, etc...).

E.g.,  Object 1 has properties w, x, y, and also z.  Object 2 has properties w, x, y, and also z.  Object 3 has properties w, x, y, and also z. (HP3) having properties w, x, y is strongly predictive of having property z.  Since Object 4 has properties w, x, y (C) it must also have property z.

D.  Diversity Among Cases:  The greater the diversity among cases that exhibit the relevant similarities (i.e., establish that properties w, x, y are relevant to having property z), the stronger the argument.

Common uses:
Arguments from analogy are often used to argue that
(1) a new policy/idea/plan will or won't work because it shares relevant characteristics with a previous policy/idea/plan;
(2) a something is good/bad/beautiful/ugly (i.e., value judgements) because it shares relevant characteristics with something we ascribe those values to.

A counter to an argument from analogy hinges on showing that having one set of properties (p, q, r, z) doesn't mean that every object with properties p, q, and r will also necessarily have property z.
In the case of the argument from design, another major flaw is that there is a disanalogy between inanimate objects which are unable to pass on complexity and living organisms which are able to reproduce and pass on complexity (and possibly become more complex over time). Disanalogies arise when we show that the properties under consideration (complexity and purposefulness) aren't necessarily relevant to having some other property (intelligent designer).

HW 15A
p. 286 Ex 11B  2. (b) 3. (a), (b), (c), (d)

Take-Home Final Due Midnight Monday May 12

The Take-Home Final Is Due by Midnight Monday May 12

Option 1:  Investigate an issue and evaluate competing arguments and claims.

For those of you interested in picking a topic and investigating it, here are some issues that I think might be interesting to cover. You are of course welcome to come up with your own.  I think the best issues are those where there are not only disputes over the facts but also over the moral relevance of the facts.

If you have a grade below a 'B' in the course I strongly suggest you do not choose Option 1.

If you would like to do option 1, you must consult with me about your topic and give me an outline for your approach.

List of Suggested Issues:
Bundy Ranch
Nuclear Waste
Nuclear energy/safety
Anthropogenic Global Warming
Anti-Vaccine
Minimum Wage laws
Paleo diet (or any diet)
Atkins diet
GMO safety or environmental impact
Flat tax
Drones


Option 2:  Standard Take-Home Final 

Part 1:  Misleading Comparisons and Slanting by Omission
A.  Arthur the Alien is planning on moving his family from a galaxy far far away to earth.  One problem he has is to figure out which country he should live in.  The most important quality he's looking for in a country is the one that will give him the best chance at a high standard of living.  To make his decision he looked at a recent study comparing the average family incomes between different countries found that the average family income in country A was $70 000.00 US/year while in country B it was $50 000.00US/year.  Identify and briefly explain 3 important additional pieces of information that Arthur the Alien would have to know in order for this report to be useful in choosing between Country A and B.

B:  In the far away land of Bugabuga there are two tribes: The Lupalupas and the Tikitakas.  Recently some anthropologists conducted an IQ test on all 12 year-old children from both tribes.  It turns out that 70% of those children who scored in the top quintile are from the Lupalupa tribe.  When the anthropologists published the results, the Lupalupa tribe bragged to anyone who'd listen that on-average, their 12-year olds have higher IQs than those belonging to 12 year olds in the Tikitaka tribe.  The Tikitaka only shook their head and laughed "typical example of the Dunning-Kruger effect."  What mistake have the Lupalupa made in their reasoning?

C:  Evil Empire Pharmaceuticals has just developed a new vaccine that is almost 100% effective against disease X.  The problem is that it causes brain damage in 1/1 000 000 people who get the vaccine. Would you get your child vaccinated?  What additional information would you need to know in order to make the decision?


Part 2: Name That Fallacy (From the whole course):
A:  This passage is from an article in a prominent anti-vaccine website.  (a) Which fallacy is being committed? (b) To support the claim that vaccines are ineffective, what additional piece of information would have to be true? (Hint: Think about "the full data set")

Let's fill in the data that so obviously got flushed down the memory hole by this irresponsible piece of CNN 'reporting.'

First, we should acknowledge one underreported fact of immunology: vaccine-induced antibody elevations do not guarantee real world protection against the pathogen the vaccine is intended to immunize us against, which is the only true measure of their value.

This is not a new observation. It goes back decades, with a 1990 study published in the Journal of Infectious Diseases finding that even though 95% of a population of urban African children had measles antibodies after vaccination, vaccine efficacy was not more than 68%.[1]

B: Prestige Properties now has a policy of only investing in development projects that are environmentally friendly and sustainable.  Before you conclude that Prestige Properties actually care about the environment you should know that they used to be the biggest slumlords in the county.

C:

 

D:

E:  "Send aid to Africa?  We should be helping our own citizens."

F:  "The counties of Michigan clearly need the ability to raise additional sources of revenue, not only to meet the demands of growth but also to maintain existing levels of service.  For without these sources those demands will not be met, and it will be impossible to maintain services even at present levels."

G:  You might think that nuclear energy is safe and that's fine.  I happen to disagree.  After all, it's a matter of opinion.

H:  Almost 80% of Americans believe that the US government is covering up evidence of UFOs.  Clearly we have been visited.




Part 3:  Do You Haz Science?
A:  This headline occurs in an article from one of the most prominent anti-vaccine websites.

Measles Vaccine Failures Documented for A Quarter of A Century, Around the World

Read one of the actual studies they cite as evidence and suggest why this headline misinterprets the study's findings and suggest a headline that is more consistent with the study.  [Technical language help:  "seropositive" means that antibodies were present in the blood.]

B:  (a) Watch the video below.  (b)  Do some online research and based on that research and concepts of standards for scientific evidence discussed in class, answer the following questions:

i)  What is the quality of the evidence supporting the claims that DCA cures cancer in humans?

ii)  What is the quality of the evidence supporting the claim that DCA has no negative side effects in humans? Is there any evidence to the contrary?  What is the quality of that evidence?

iii)  The video makes an appeal to conspiracy and/or greed to explain why major pharmaceutical companies aren't pursuing research in DCA.  Based on your research might there be other explanations for their lack of interest in DCA as a cancer drug?

C:  The following study/meta-analysis is often cited by US anti water fluoridation groups as support for the idea that fluoridation in US municipal water supplies is harmful and should be removed.  Read the study abstract, the introduction (the section right after the abstract) and paragraph 2 of the methods. Using the concepts we've discussed in class answer the following:

i) Why does the meta-analysis arrive at the results that it does?

ii)  Are the anti-fluoridationists correct in citing this analysis as evidence for their view that fluoridation in US municipal water supplies should be removed.

iii)  Suggest a more appropriate conclusion that can be drawn from this study in regards to fluoridation in drinking water.

D:  Polling Problem:  In the 2012 election the Republican pundits grossly miscalculated the election results.  One notable difference between how the Democrats and the Republicans conducted their polls is that the Republicans called only land lines while the Democrats also called cell phones.  Using the concept of selection bias, suggest how this data collection method could account for the Republican's failed predictions.

Part 4:  Arguments from Analogy
(a) Evaluate the argument as we have done in class for arguments using this scheme (b) what are the claimed similarities and how relevant are they, (c) what are the differences and how relevant are they, (d) once you've put the argument into standard form for analogies, evaluate whether S and/or T really do have the properties being ascribed to them, (e) based on your evaluation, how strong is the argument?

Argument 1 (This is a meme, not an actual study)
An economics professor at Texas Tech said he had never failed a single student before but had, once, failed an entire class. The class had insisted that socialism worked and that no one would be poor and no one would be rich, a great equalizer. The professor then said ok, we will have an experiment in this class on socialism. All grades would be averaged and everyone would receive the same grade so no one would fail and no one would receive an A.

After the first test the grades were averaged and everyone got a B. The students who studied hard were upset and the students who studied little were happy. But, as the second test rolled around, the students who studied little had studied even less and the ones who studied hard decided they wanted a free ride too; so they studied little ...

The second Test average was a D! No one was happy. When the 3rd test rolled around the average was an F. The scores never increased as bickering, blame, name calling all resulted in hard feelings and no one would study for anyone else. All failed to their great surprise and the professor told them that socialism would ultimately fail because the harder to succeed the greater the reward but when a government takes all the reward away; no one will try or succeed.

Argument 2
The federal budget is just like a family budget, and we in government must tighten our belts and live within our means just like families do.

Part 5: Identify that Argument Scheme!
(a) Identify the argument scheme and rewrite the argument in its standard form (b)  explain why these instances fail as good instances of the argument scheme, (c) name any fallacies relevant to inductive reasoning, and (c) suggest additional information could be included to strengthen the claim (where possible).

(1)  There's no good evidence to show that aspartame is safe for human consumption, therefore we shouldn't consume it.

(2)   82 percent of people with tattoos prefer hot weather over cold, compared with 63 percent of people in general.  Therefore, preferring hot weather causes people to get tattoos.  Based on a survey of 114 people with tattoos and 579 people in general.

(3)  I get headaches after drinking diet soda, therefore aspartame causes headaches.

(4)  About 1/2 the students I know receive government financial aid, therefore it's reasonable to conclude that 1/2 the students at UNLV receive government financial aid and are socialists.

(5)  There are several cases where multiple people have sighted an object in the sky which they couldn't identify, therefore those objects are alien space crafts.

(6)  All my philosophy professors think Aristotle is better than Plato, therefore most philosophy professors must prefer Aristotle to Plato.

(7)  A study demonstrated that 90% of all pedophiles consumed pornography before the age of 12.  When they reported this study, the media concluded that early exposure to pornography causes pedophilia.