Behavioral research has shown that 12- but not 9-month-olds imitate an unusual and inefficient action (turning on a lamp with one's forehead) more when the model's hands are free. Rational-imitation accounts suggest that infants evaluate actions based on the rationality principle, that is, they expect people to choose efficient means to achieve a…

Efforts to link media use to adolescents' sexual initiation have produced somewhat inconsistent results, perhaps as a result of the limited framing of the question. This study sought to expand current approaches by sampling college students instead of high school students, by investigating a range of sexual behaviors and media formats, and by…