Dr Spock Is Interested in Examining Genetic and Environmental Influences

Multiple Choice

Dr. Spock is interested in examining genetic and environmental influences on enjoyment of reading. She has decided to include fraternal twins in her study. If she finds that the correlation between fraternal twins on enjoyment of reading is higher than is the correlation between _____ on this measure, then she has evidence for the influence of _____.

A) identical twins; environment and genetics
B) nontwin siblings; environment and genetics
C) fraternal twins reared apart; environment
D) identical twins reared apart; genetics