PrepTest 158

Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Rational-choice theory people's support for a political party is entirely explained by voters making decisions based on their economic self-interest. Many sociologists say this is wrong because it's not possible for a complex phenomenon like the rise of a political party to be caused by a simple phenomenon.

Strategy Overview:

1. Argument or facts in passage?
   1. If argument, identify premises and conclusions
2. Sufficient/necessary conditions in the passage?
   1. If so, diagram statements and draw any deductions
3. Use anticipation to find the answer choice that is absolutely 100% true

Answer Anticipation:
This passage describes two groups' ideas and how they support them, but no overall conclusion. So this passage presents a set of facts, not an argument.

From these facts, we're asked to infer what the sociologists must believe is true. The principle they use to justify their opposition to rational-choice theory is presented as a conditional statement, so we can diagram it:

Complex Phenomenon → NOT Caused by Simple Phenomenon

The sociologists believe that this principle shows why rational-choice theory isn't justified. What needs to be true for this rule to undermine rational-choice theory, which holds that support for a political party is entirely explained by voters' personal economic interests? Well, the sociologists say that the rise of a political party is a complex phenomenon, and they oppose rational-choice theory. So they must believe that the cause posited by rational-choice theory — voting based on your economic self-interest — is a simple phenomenon, not complex enough to cause a complex phenomenon.

Answer Choice Explanation:
Right away, we get our anticipation. If voting based on personal economic interest was a complex phenomenon, the sociologists couldn't use their principle to undermine rational-choice theory. Because they believe the principle undermines rational-choice theory, the sociologists must believe voting based on rational economic interest is not a complex phenomenon. This is correct.

Key Takeaway:
Disagreements (e.g., "Some people say this, but clearly they're wrong") show up all the time on Logical Reasoning questions. When a disagreement appears on a question, it's helpful to ask, "What does this author think is true, then?" As in, if "some people are wrong," what does the author think is right? But be careful when you do so! Make sure to carefully review the belief the author thinks is wrong. Without reviewing rational-choice theory, it would be easy to assume that these sociologists believe that economic self-interest doesn't play any role in voters' decision-making, which could have led us to the select (E).

The sociologists seem to believe complex phenomena have complex causes, but nothing here says they believe each phenomenon has more than one cause. They may believe some phenomena have one complex cause.

Religion and culture were not mentioned in this passage at all! So this answer choice is simply not supported by the passage.

This contradicts the sociologists' premise. The sociologists use the popular support of a political organization support as an example of a complex phenomenon.

Tempting trap here, since we know the sociologists oppose rational-choice theory. However, this answer choice subtly but significantly misdescribes what rational-choice theory is. Rational-choice theory holds that popular support for a political party is entirely ("sufficiently") explained by voters making decisions based on their economic self-interest. The sociologists certainly have issues with that. But even though they don't think popular support for a political party isn't entirely explained by that, they could still think that economic self-interest influences voters' decisions. The sociologists think that considerations of economic self-interest don't entirely cause the rise of political parties, not that those considerations never enter into the equation at all.