Comparisons of hormone production in boys and girls show that

Behavioral geneticists are finding that within a group of people, about __________ of the variation in personality traits such as happiness is attributable to genetic differences. 

When two psychologists surveyed 275 freshmen at Cornell University, they found that 

Researchers have found that “baby talk” by parents

__________ is the understanding that the physical properties of objects, such as the number of items in a cluster or the amount of liquid in a glass, can remain the same even when their form or appearance changes. 

In psychoanalysis, which component of personality is present at birth and is the reservoir of unconscious psychological energies and the motives to avoid pain and obtain pleasure?

According to the section in your textbook on lie detection

An adolescent has just experienced menarche.  This means that

The polygraph is based on the assumption that a person who is guilty and fearful will have

Culture can be defined as a program of shared __________ that govern the behavior of people in a society, as well as a set of shared values and beliefs.