Passage Summary: Researchers found that people with hyperactivity have less brain activity in a specific area, so they concluded that this low brain activity is what makes them hyperactive.

Conclusion: Reduced activity in the premotor cortex is a cause of hyperactivity.

Reasoning: A study comparing hyperactive and nonhyperactive adults found that those with hyperactivity had significantly lower brain activity in the premotor cortex.

Analysis: This argument falls into the classic trap of assuming that because two things happen together, one must cause the other. The researchers found a correlation between brain activity and hyperactivity but jumped to the conclusion that the brain activity is the cause. To weaken this, look for an answer that suggests the reverse—perhaps the state of being hyperactive actually causes the brain activity to drop—or points to an external factor that causes both.