14.9: Some Case Studies

The following letter to the editor is fun to read, and analyzing it will demonstrate all the points we’ve made about using your creative abilities in justifying causal claims. For background, the Planned Parenthood organization, which is attacked in the letter, is the largest dispenser of birth control information in the United States.

The point of Pence's letter is primarily to state her beliefs and to give a few suggestive reasons; she is not trying to provide scientific proofs for her beliefs. Nevertheless, if she expects readers to change their own beliefs and adopt hers, as she appears to want, then she has the burden of proof and should offer some good reasons. What reasons does Pence offer? In her early sentence that begins "Hasn't it struck anyone a little bit strange...," she suggests there are positive associations of the following sort:

Pence implies a causal connection in these associations when she says, "Are we so far down the road to self-indulgence that we don't recognize simple cause and effect?" Assuming that the positive associations can be shown to exist (and a logical reasoner would like to be satisfied of this), the next step for the logical reasoner is to ask whether there are plausible alternative explanations for these associations. Maybe the associations are accidental. Or maybe the causal connection goes the other direction; for example, the rise in teenage pregnancy might be causing Planned Parenthood to be invited to offer more sex education classes in order to reduce the pregnancy rate. Thus, there are serious alternative explanations that the author apparently has not ruled out. That makes her causal claim weakly justified. However, caution is called for because:

In the next sentence of her letter, Pence implies, between the lines, that legal abortions are causing three problems: child abuse, symptoms of high stress in women, and symptoms of emotional disorders in women. Can you imagine other possible causes for these effects that she hasn't ruled out? For example, what else can cause high stress?

In short, there are serious problems with the causal reasoning in this letter. As a result of our analysis, it is clear that the letter is basically stating opinion, not fact.

Exercise \(\PageIndex{1}\)

Pence has several suggestions for what should be done about all the problems mentioned in her letter to the editor. Which one of the following is definitely not one of her direct or indirect suggestions?

a. Children should stop acting like animals.
b. Stop sex education classes.
c. Stop funding Planned Parenthood.
d. Planned Parenthood should be stopped from performing its illegal abortions.

Answer

Answer (d). The letter did not suggest that Planned Parenthood should be stopped from performing illegal abortions; the focus was on legal ones

Here is a speech that might have been given to the County Sheriffs Association of the United States. It contains a report of a scientific study of crime. Be on the lookout for mistakes made by John Doe who misunderstands the report; he understands some things and misunderstands others.

Slowly, science is figuring out crime. A reputable, independent, Italian social research organization found that 66 percent of criminals in U.S. jails did not have a high school degree. To me, this shows that lack of education is partly to blame for crime in our nation. Isn't it time to act on the causes, not just the symptoms of crime?

Suppose John Doe is asked to comment on the quality of the speaker’s preceding argument, and he gives the following response.

(1) The first problem with the study is that it was conducted on convicted criminals, which is not a representative sample of the U.S. (2) The study did not state the age of these criminals; maybe they were all seventeen and were not old enough to complete high school but were in the 11th grade. (3) They should also do a study on the people who had not finished high school but who were not convicted criminals. (4) They cannot say that lack of education is the cause of crime in other countries because some countries do not have the funds or desire to educate their population. (5) How do we know where this firm got its information? (6) Maybe they just got it from one prison. (7) And why should it be an Italian firm? Italians don't live in the U.S. and do not understand us Americans. (8) Lack of money causes crime, not just lack of education.

John has missed some of the key things that should have been said about the report. There are other errors. What? Can you suggest any improvements in his answer? For our final activity in this chapter, let’s dig deeply into this situation. The principal difficulty with John Doe's response to the report is its failure to mention the two main errors contained in the report. First, the 66 percent statistic by itself does not establish a correlation between lack of high school education and being convicted of crime in the U.S. Second, even if it did, there is no basis for jumping to the conclusion that lack of education is partly causing U.S. crime.

Why doesn't the 66 percent statistic make the case for the correlation? For it to do so, you'd need to know that 66 percent is unusual. Maybe 66 percent of all Americans don't have high school degrees. If so, there is no correlation. Assuming for a moment that there is a significant correlation, it still isn't a basis for saying that lack of education partly causes crime, because there are other reasonable explanations that haven't been ruled out. Perhaps poverty, greed, and bad genes cause both the crime and the lack of education. Or maybe becoming a criminal causes lack of education, not the other way around.

Let's now analyze John Doe's response sentence by sentence. Sentence (1) is mistaken in saying that the sample is not representative of the U.S. The real goal is to be representative not of the U.S. but of U.S. criminals. The target population of the statistical reasoning is convicted criminals in the U.S., not everybody in the U.S.

There is also a problem with sentence (2). Doe is complaining that he doesn't know the ages of the criminals whose education was examined. But he mistakenly implies that his lack of information is a sign of some error in the study. He may be thinking of the correct, but minor, point that the reader is not given enough information to tell whether the sample is representative of U.S. criminals. If the sample were only of seventeen-year-olds, undoubtedly it would be non-random and apt to be unrepresentative of U.S. convicted criminals. However, Doe shouldn't make too much of this. His answer would be better if it showed some awareness of the fact that there is no reason to believe the sample was of seventeen-year-olds because the study was done by a "reputable... research organization," which presumably means a competent one. Also, Doe gives no indication that this is in fact a minor point.

The point in sentence (3) is not made clearly. Yes, the study also should have included people who had not finished high school but who were not convicted criminals, but why should it have done so? The point would be to make sure that the figure of "66 percent" is unusual. A finding that significantly fewer than 66 percent of the unconvicted people had not finished high school would demonstrate the correlation that the speaker implies does exist—namely, that there's a negative correlation between crime and education. Doe should say all this explicitly, but he doesn't. In addition, if that is Doe's point in sentence (3), it is a major point and should have been emphasized, say by placing it first, not third.

Sentence (4) complains that some countries are too poor or are not as motivated as the U.S. to educate their citizens. That comment may be true, but it is irrelevant to whether the lack of education causes crime; it speaks only to why there is lack of education, which isn't the issue.

In sentence (5), Doe says we aren't told the source of the study's information. This would be a minor but correct statement by itself, but when (5) is accompanied by sentence (6), which says the study might have been done in only one prison, it makes the mistake of implying that the sample was too small. Doe's comments fail to recognize that the sample is probably large enough, simply because it is common knowledge to social researchers that the U.S. has many prisons, and a reputable research organization would not have obtained its data from just one prison. The reason that sentence (5) would be a minor point by itself is that there isn't much need for the reader to know where the organization got its information; what is more important is whether the organization is good at its research and whether it can be counted on to have made a good effort to get a representative sample of U.S. criminals.

Sentence (7) is mistaken because there is no good reason why Italians cannot do high-quality social research on Americans.

Sentence (8) states, "Lack of money causes crime, not just lack of education." This is probably true, but if off the mark. The speaker said only that lack of education is partly a cause of crime; the speaker didn't rule out poverty as another cause. Doe's answer mistakenly implies that the argument did rule out poverty.

In summary, Doe missed or didn't adequately express the main points, and most of his other points were mistaken, too. Note how this evaluation of Doe's evaluation addresses many topics of logical reasoning: sticking to the issue, arguments from authority, vagueness, implication, identifying arguments, and distinguishing cause from correlation.