When "bright" and "dull" strains of rats were reared in enriched environments designed to stimulate learning, __________ in terms of navigating a maze.

Longitudinal epidemiological studies that begin with people who are disease-free and are then followed for a period of years are called:

A) retrospective studies. B) prospective studies. C) correlational studies. D) cross-sectional studies

What is a central defining characteristic of the basic emotions? a. They are demonstrated as early as two or three days after birth

b. They trigger activity in the same facial muscles, though in slightly different ways. c. They activate a common part of the brain that is responsible for all emotions. d. They are experienced by human beings worldwide.