Many psychologists today believe that Freud's most important contribution to the science of psychology resulted from his emphasis on

In some cases, obsessive-compulsive disorder has been traced to

a. birth trauma. b. spinal cord injury. c. a defect in chromosome 16. d. early-onset dementia. e. brain tumor.

The practice of physiognomy, as well as that of phrenology,

have been summarily discredited by modern scientific research. As it turns out, the bumps on a person's head and one's facial characteristics give virtually no information about their personality characteristics. This is an important reminder of the importance of the critical thinking principle of A) falsifiability. B) correlation versus causation. C) extraordinary claims. D) ruling out rival hypotheses.