LSAT 117 | Section 2 | Logical Reasoning: Q20

LR Question 20 Explanation

QUESTION TEXT: Scientist: My research indicates that children …

QUESTION TYPE: Weaken

CONCLUSION: The gene variant causes an inclination toward thrill-seeking behavior.

REASONING: Children who engage in impulsive behavior similar to adult thrill-seeking behavior are twice as likely to have a certain gene variant.

ANALYSIS: The scientist observes a correlation between impulsive children and this gene variant. They, then, conclude that the gene variation causes an inclination toward thrill-seeking.

There’s actually two issues here:

1. A correlation is being treated as proof of causation.
2. The scientist assumes that the impulsive behavior identified in children is a real and reliably identifiable phenomenon that is meaningfully connected to adult thrill-seeking behavior.

___________

1. Many impulsive adults may lack the gene variant, but the scientist never claims that all impulsive or thrill-seeking people possess this gene. A cause doesn’t need to explain EVERY case.
2. CORRECT. This gets at the second issue I identified above. If it’s impossible to reliably distinguish impulsive behavior from other behavior, then we can’t be confident that the study actually identified the group of children it claims to have studied. The alleged correlation may therefore be based on a poorly defined or misidentified group, substantially weakening the inference to causation.
3. This answer sounds attractive, but it only says that adults describe impulsive children as thrill-seeking. It’s just about labels. The scientist’s evidence concerns the children’s behavior itself, not the terminology adults use to describe it.
4. The scientist never claims that every impulsive child becomes a thrill-seeking adult. The conclusion concerns an inclination, not a guaranteed life outcome.
5. A gene can be associated with many behaviors. Showing that this gene also correlates with other behaviors doesn’t undermine the possibility that it also contributes to thrill-seeking behavior. To weaken, we would need evidence that another factor explains the correlation or that the observed correlation is unreliable.