According to ___ theory, wariness of outgroup members—and even the propensity to take hostile actions against them—was so essential to human’s survival in earlier epochs that nature favored those who engaged in intergroup conflict over those who were pacifistic.

_______ is a unique set of behaviors and enduring qualities that influence the way a person adapts to her/his environment

a. Instinct b. Personality c. Trait d. Motivation

Which of the following is the best support for the possible addictive nature of marijuana?

a. Marijuana is self-administered by both humans and lower primates. b. Most chronic users experience noticeable withdrawal symptoms when drug use stops. c. Tolerance develops to the euphoric effects fairly rapidly. d. Marijuana causes physiological dependence.