Violation of Expectancy and Frustration in Early Infancy

Instrumental responses to both learning and extinction were examined in a group of infants aged 2-8 months. Eighty infants, divided equally among 4 age groups (2, 4, 6, and 8 months), participated in a contingency learning task. Forty-eight Ss received an audiovisual stimulus contingent on arm movement, and 32 Ss served as a yoked control group. Findings indicated that (a) infants in the contingent group showed a significant increase in their rate of arm pulling as a function of contingent stimulation; (b) with the cessation of stimuli during extinction, contingent subjects at all ages showed a significant increase in response rate from the learning phase; and (c) the ability to learn an instrumental response and reactivity to the violation of a learned expectancy were not related to temperament differences. The results indicate that exposure to extinction, a period in which the infant's expectancy regarding contingent outcomes is violated, produces increased responsivity.