Why is genetic/evolutionary explanation of behaviour difficult to test experimentally in humans?

• A. They can't easily test long-term selection in humans
• B. They ignore long timescales
• C. They can be tested directly in labs
• D. They only apply to animals

Answer: (A)

Genetic and evolutionary accounts rely on processes that unfold over many generations. In humans, we can’t run long-term, generation-spanning experiments that would show how selection shapes specific behaviours, because it’s ethically and practically impossible to control reproduction or observe outcomes across generations. This means we can’t test these ideas directly in people through experimental designs. Instead, researchers use indirect evidence from sources like cross-species comparisons, fossil and historical data, and genetic studies to infer how evolution might influence behaviour. The key barrier is the impossibility of observing or enforcing long-term selection within a human lifetime.