Some experts have said that the diagnostic criteria for somatic symptom disorders are so broad that _____ of patients with cancer and heart disease would meet criteria for the condition.

All of the following have been implicated in the development and maintenance of somatic symptom disorders EXCEPT a. the additional attention one receives when sick

b. a specific hypochondriac gene. c. the high incidence of disease in the family during the hypochondriac's childhood. d. stressful life events

Some evolutionary psychologists argue helping behavior can be explained by the mechanism of natural selection so long as the unit of selection is considered to be the:

a. social unit b. individual c. cultural group d. gene