In which substage did Piaget suggest that children can first imitate the facial expressions of others?

To determine the range, we simply

a. subtract the highest score minus the lowest score. b. subtract the lowest score minus the highest score. c. need to know the lowest and highest scores. d. average the lowest and highest scores.

An in-depth study by Lewis and colleagues of 12 convicted murderers diagnosed with dissociative identity disorder (DID) looked into their backgrounds. The study found strong evidence that each was severely abused, both physically and sexually. Why does the text refer to this study as "flawed."

A. Malingerers were studied separately from the larger group of DID sufferers. B. Malingerers were excluded from the study. C. There was no control group of murderers without DID. D. There was no control group of DID sufferers who were not murderers.