Salma's 1-year-old son hums when he plays with toys. Salma responds to this behavior by smiling and talking to the baby, and so he keeps humming to gain Salma's attention. In the context of the learning perspective on human development, this scenario exemplifies the concept of:

Although this conclusion is controversial, some psychologists believe that individuals with dissociative identity disorder develop multiple personalities

a. as a way of pushing traumatic events out of conscious awareness. b. because they are reinforced for doing so, through the attention they receive. c. as a result of having been hypnotized by close friends or relatives. d. as a result of severe substance abuse during childhood.

Jocelyn is 16 and hoping to jointhe Peace Corps after college and work in Bolivia. She has never

traveled there, but she has read a lot about the Peace Corps and the work they are doing, and Jocelyn can see herself working there teaching English. Which stage of cognitive development is she in? a. sensorimotor b. formal operational thought c. concrete operational thought d. preoperational thought