Which type of study provides the clearest way to address the nature-nurture question?

When six-month-old infants are given pictures of attractive and unattractive adult faces to look at, they tend to __________

a) spend an equal amount of time looking at both types of faces. b) spend more time looking at the attractive faces. c) spend more time looking at the unattractive faces. d) not pay attention to either type of picture.

When present in children during the early elementary school years, which of the following is

the most important predictor of early-onset conduct disorder and of the continuation of disruptive behaviors in adolescence and beyond? a. Instrumental aggression b. Hostile aggression c. Physical aggression d. Covert aggression e. Relational aggression