In the United States, almost ________ of teenagers will become pregnant before they are 21 years old

The text describes a study in which infants were shown pictures of several different horses. Then they were shown a picture of a horse and a picture of a different animal, such as a giraffe

What research technique did this study employ to determine how infants learn to categorize objects? a. classical conditioning b. reinforcement c. habituation d. punishment

What percentage of children in the United States lives with a stay-at-home parent?

A) one-half B) one-third C) one-quarter D) one-fifth