Which of the following procedures employs the gradual alteration of the intensity of a stimulus?

When we examine changes over the years in the percentage of high school seniors who say they have smoked marijuana, we find a clear inverse (mirror-image) relationship to

A. alcohol use. B. perceived availability of marijuana. C. perceived risk of harm in using marijuana. D. the nation's economy.

The despair of a person who is in Erikson's final psychosocial crisis is most likely caused by

a. their fear of dying. b. their decrease in mental ability and physical stamina. c. their incomplete resolution of earlier developmental crises. d. societal discrimination against the elderly. e. lack of social support from friends and family members.