At what median age do adults in the United States show the onset of mood disorders?

Adoption studies reveal that

A) adopted children show a significant decline in IQ across middle childhood and adolescence, regardless of rearing conditions. B) children of low-IQ biological mothers do as well as children with high-IQ biological mothers when placed in similar adoptive homes. C) genetic factors play a much greater role in IQ than environmental factors. D) when children of low-IQ mothers are adopted at birth by parents who are well above average in income and education, they score above average in IQ during the school years.

Bettelheim's diathesis-stress theory of hyperactivity suggests:

a) Hyperactivity arises from a predisposition for the condition in environments where the parents are passive. b) Hyperactivity is an interaction between a predisposition for the condition and authoritarian parents. c) Children's hyperactivity are based upon unconscious drives that are manifest during times of stress. d) Hyperactivity is pervasive and due to a biological factor that arises during stress.