Pacey avoids riding all the rollercoasters at Carowinds because he is afraid of heights. This is an example of:

By what age does your text suggest that most infants develop the understanding that objects still exist even when they are out of the infant's sight?

A) 3 months B) 4 months C) 9 months D) 12 months

In the last 20 years, social psychologists have improved the representativeness of their research samples in which of the following ways?

a. by including many more members of ethnic minority groups in their samples b. by decreasing their reliance on older adults as research participants c. by improving the gender balance of their samples d. all of the above