Prejudices and rational thinking

I took these two examples from Steven Pinker’s book Rationality (p. 294):

1) If college admissions are fair, then affirmative action laws are no longer necessary.
College admissions are not fair.
Therefore, affirmative action laws are necessary.
[affirmative action laws: laws to improve employment or educational opportunities for members of minority groups and for women]

2) If less severe punishments deter people from committing crime, then capital punishment should not be used.
Less severe punishments do not deter people from committing crime.
Therefore, capital punishment should be used.

What do you think: Are these arguments sound? Well, if you are progressive (in European terms) or liberal (in American terms), probably you’ll think that the first reasoning is sound (correct) and that the second one is unsound (false). On the other hand, if you are conservative (and in Europe rather ultra-right), probably you’ll think that the first reasoning is not correct while the second reasoning is okay. (see Pinker, p. 294) Apparently, the truth of the reasonings above depends on your political stand. Right?

In order to investigate this question, take this example:

3) If it rains, the streets become wet.
It doesn’t rain.
Therefore the streets don’t become wet.

What do you think of example 3? Hmm, you’ll think, whether you are progressive, liberal, conservative or ultra-right, that 3) need not be true, for it is quite well possible that a car sweeping and cleaning the streets passes, and that this car uses water to clean the streets, which makes the streets wet. Therefore, the streets can be wet, although it hasn’t rained. So argument 3 is unsound, isn’t it?

Let me now reformulate example 3 in order to bring it in line with examples 1 and 2. Let me replace “wet” by “not dry” and “not wet” by “dry”:

4) If it rains, the streets don’t stay dry.
It doesn’t rain.
Therefore the streets stay dry.

For the same reason why argument 3 was unsound, also argument 4 is unsound, so false: It is quite well possible that a car sweeping and cleaning the streets passes and that this car uses water to clean the streets, so that the streets don’t stay dry.
We can argument 4 also write this way, by replacing “it rains” by “P” and “the street stays dry” by “Q”. Then we get:

5) If P then not Q
Not P
Therefore Q

As we just have seen, this argument is unsound (false).

Let us now return to examples 1 and 2. A close look at them makes clear that both 1) and 2) have the form of the unsound argument 5. For instance, in example 1 “college admissions are fair” is “P” and “affirmative action laws are necessary” is “Q”. I leave it to you to fill in P and Q for example 2. Therefore, since reasoning 5 is unsound, also examples 1 and 2 contain unsound reasonings, despite your political stand. However, we often see that, as soon as a reasoning becomes a little bit complicated or a little bit obscure and difficult to follow without thinking a little bit deeper, people stop thinking. Or people do not simply think “That cannot be right, or maybe it nevertheless is? Let’s find out what the problem is.” No, they think “This should not be right, and therefore it isn’t.” (or “This should be right, and therefore it is.”) Then they stop thinking further and adapt the facts to what they think that the facts are. In other words, they found their reasoning and view of the facts on prejudices. They walk into the trap of the “myside bias” (Pinker’s term), often with open eyes. I am the first to admit that I, too, regularly make this type of mistake, for reasonings are often not really clear and easy to get a grip on. Often prejudices commandeer the mind. So, people tend to think what they think that they must think for all kinds of reasons, for example because they really, “autonomously” think so; under group pressure; or because they have learned to do so; or from habit; etc. All kinds of people suffer from the myside bias, despite race, gender, cognitive style, education level, whether you are a logician or not, etc. You can see the phenomenon everywhere, like in the pandemic discussions, the view of the Russia-Ukraine War, the value of simple political measures, and what more. Open your mind to what you don’t believe.