LSAT 7 | Section 1 | Logical Reasoning: Q10

LR Question 10 Explanation

QUESTION TEXT: A large group of hyperactive children whose regular …

QUESTION TYPE: Flawed Reasoning

CONCLUSION: Food additives contribute to behavior issues in hyperactive children.

REASONING:

• A group of hyperactive kids eating lots of additives were observed.
• Nearly 60% had behavior issues.
• They switched to a low-additive diet and only 30% had behavior issues a few weeks later.

ANALYSIS: This is a classic causal flaw. It infers causation from correlation, but there are many problems here.

If you know anything about scientific study, you know every experiment needs a control group. Otherwise we don’t know whether the change can actually be attributed to the additives. Maybe the kids would have improved anyway over time, or maybe something else about the study improved their behavior.

The conclusion that additives cause behavior issues isn’t well-supported because the study didn’t control for other possible explanations.

___________

1. This doesn’t affect the conclusion because the argument never claimed a proportional relationship. It’s about whether additives contribute at all.
2. CORRECT. Without a control group, there’s no way to know if the behavior would have improved even without the diet change. The argument incorrectly assumes the diet was the cause of the improvement.
3. The argument relies on percentages, and the conclusion doesn’t depend on knowing the exact number of children.
4. The conclusion is that additives can contribute, not that they affect every child. This doesn’t weaken the reasoning.
5. Even if some children actually worsened after the diet change, we still know that the overall percentage decreased. So this doesn’t get at the flaw.