Explanations of animal behavior that rely solely on instinct would have difficulty interpreting the fact that mother chimpanzees show their young how to use stone tools to open nuts

To control for this bias in drug studies, participants are kept blind as to whether they are receiving the active drug or placebo:

a. personal b. observer c. expectancy d. placebo e. confounding

The distinction between ________, on the one hand, and ________, on the other, is of central importance to social learning theorists

a. learning; performance b. positive reinforcement; negative reinforcement c. reinforcement; punishment d. generalization; discrimination