According to the self-medication theory, the motivation to use substances stems from a deep-seated desire for self-destruction.

The scientific study of the changes that occur in people as they age from conception to death is called __________

a) abnormal psychology. b) gerontology. c) developmental psychology. d) maturational studies.

During infancy, the brain grows until it is approximately

a. 50 percent of an adult's brain by the age of 3 years b. 30 percent of an adult's brain by the age of 3 years c. 50 percent of an adult's brain by the age of 1 year d. 25 percent of an adult's brain by the age of 1 year