Incentive values have little to do with how a motive is expressed in behavior

The episodic nature of obsessive-compulsive disorder symptoms is thought to be related to

a. cycles of activity in neurotransmitters. b. changing levels of environmental stress. c. changes in the ability to suppress thoughts. d. a rebound from attempts to suppress strong emotion.

Compared to white children, black children from both low- and middle-income families

a. had lower levels of aggression if they slept poorly. b. had higher levels of aggression if they slept well. c. did not differ in aggression levels from white children if they slept well. d. had the same levels of aggression regardless of whether they slept well or not.