William is participating along with a group of adolescents trying to lose weight. One of his assignments is to keep a diary of his food intake and the times that he eats daily. This can be considered an example of what type of research?

Aging is not, by itself, a cause of major depressive disorder (NIMH, 2009). Rather than simply focusing on advancing age, it may be that some of the psychosocial changes that accompany aging (Yang, 2007) prompt depressive episodes. Which of the following best illustrates this concept?

a) Loss of a good friend b) Circumstance of giving up driving c) Victim of a natural disaster d) All of the above

In middle childhood, __________ contributes to the development of trust and sensitivity

A) friendship B) informal peer group membership C) peer conformity D) formal group membership