The presence of at least two distinct personalities is characteristic of

According to the principle of ecological validity,

a. experiments should be as carefully controlled as possible, in order to avoid confounding variables. b. laboratory settings should be employed whenever possible. c. behavior should be initially studied in its simplest, most basic form; more complex kinds of behavior should be studied later on. d. experiments should be conducted that will have some application to experience outside the laboratory

Which of the following statements accurately describes the incidence of mental illness following brain trauma?

A. Any type of psychological disorder, such as depression or panic attack, is a direct result of brain damage. B. Approximately 27 percent of stroke survivors attempt suicide within six months following their stroke. C. Patients who are intelligent, well-educated, and mentally active experience less mental and behavioral deterioration. D. After brain injury caused by a fall or an accident, approximately 11 percent of patients attempt suicide.