Twin studies assume that identical and fraternal twins share equally similar:
- birth weights
- personalities
- home environments
- blood groups
Show answer and solution
Correct answer: C. home environments
1. The classical twin design compares identical and fraternal twins.
2. It depends on the equal environments assumption, that both kinds of twins share similar environments.
3. Without it, extra similarity of identical twins could be due to environment instead of genes.
_Source: Wikipedia, "Nature versus nurture" (rev 1379405136), section "Heritability estimates"_