Passage Summary: Because identical twins separated at birth often act and dress alike, a psychologist argues that our personalities are hard-wired by our DNA rather than shaped by how we were raised.

Conclusion: Many human inclinations are caused by genetics rather than environmental influences.

Reasoning: Identical twins raised in different environments still show a strong tendency to have similar ethical beliefs, fashion choices, and career paths.

Analysis: To weaken this argument, we need to find a way to suggest that the environment played a bigger role than the psychologist admits. Perhaps the 'vastly different environments' weren't actually that different, or perhaps the twins were reunited later in life and influenced one another. You might also look for an answer that suggests these similarities are common among all people, regardless of genetics. The goal is to break the exclusive link the author draws between genetic similarity and behavioral outcomes.