Tantrums during toddlerhood, also known as the "terrible twos", are universal across the world

To retain behavior that has been observed, a person must:

a. first perform the observed behavior. b. reinforce the behavior directly. c. encode and symbolically represent the model's behavior. d. relate the behavior to his or her self-concept.

Contemporary views on human development focus on age-related changes that occur ____.?

a. ?from infancy to puberty b. ?during childhood and adolescence c. ?until the brain is fully developed d. ?across the entire life span