When researchers want to ensure that a certain kinds of participants in a convenience sample are obtained in particular proportions, they use

Marijuana impairs the function of which brain area?

A) Hippocampus B) Amygdala C) Pituitary gland D) Hypothalamus

Cohort effects are examples of

A) sociocultural-graded influences. B) age-graded influences. C) history-graded influences. D) nonnormative life events.