The arithmetic average of a distribution of scores is the

A) mode.
B) median.
C) standard deviation.
D) mean.

Alice is typing her term paper in the computer lab. Although a class is going on just a few feet away, she does not seem to notice. Which part of the brain allows Alice to focus on her typing and ignore the distractions that surround her?

A) reticular formation
B) pons
C) medulla
D) cerebellum

Which of the following is NOT a source of confounding variables?

A) random assignment
B) selection bias
C) placebo
D) experimenter bias

People with a low arousal level of their autonomic nervous system may show aggression as a way of seeking stimulation and excitement.

Identify a true statement about cognitive development.

A) Crystallized intelligence is the ability to process information, such as solving a math problem rapidly.
B) Fluid intelligence represents one's lifetime of intellectual attainments, as shown, for example, by vocabulary and accumulated knowledge.
C) Crystallized intelligence declines with age.
D) Fluid intelligence is more susceptible to the effects of aging than crystalline intelligence.

Psychodynamic personality theories focus on

A) an individual's freedom and potential for growth.
B) genetic factors.
C) unconscious mental forces.
D) learning.