A trait is polygenic if it is influenced:

Which person is an example of someone most likely to be involved in a case in which memories of past childhood abuse are recalled later in life?

a) Twenty-year-old Charlotte, who sought therapy for anxiety with a therapist who uses hypnosis. b) Thirty-year-old Steve, who sought therapy for symptoms that developed after serving in Iraq. c) Ten-year-old Willard, who was referred by a pediatrician for symptoms that appear to meet the diagnostic criteria for hyperactivity. d) Fifty-year-old Agnes, who fell, hit her head, and suddenly began remembering that her brother abused her sexually when she was eight years old.

According to the text, many behavioral variables, such as intelligence and memory ability,

a. are distributed along a normal curve. b. tend to have different medians and modes. c. are not usually normally distributed. d. tend to have identical means.