Physical exertion tends to increase

Longitudinal studies measuring individuals' level of moral reasoning over time found that

a. many individuals skipped at least one of Kohlberg's stages. b. it was common for individuals to regress to lower levels of reasoning. c. most individuals progress to the highest levels of reasoning. d. higher levels of moral reasoning were more common in older adolescents and adults.

Any event whose presence increases the likelihood that an ongoing behavior will recur is a(n) ________

a. conditioned stimulus b. unconditioned stimulus c. positive reinforcer d. negative reinforcer