What proportion of values falls below a z-score of -2.00?

Adoption studies are important in behavior genetics because they help to

a. investigate the effects of adoption. b. provide evidence on genetic versus environmental contributions. c. separate the MZ twins from the DZ twins. d. determine whether adoption can influence genetic makeup.

Someone whose focus is on deciding whether they want to become a gourmet chef or a race-car driver is at what stage of Erik Erikson's psychosocial development?

a) integrity vs. despair b) intimacy vs. isolation c) generativity vs. stagnation d) identity vs. identity confusion