Violation of expectancy, loss of control, and anger expressions in young infants.

This study examined facial expressions in relation to cognition in infants aged 2–8 months. Eighty infants, divided equally among 4 age groups (2, 4, 6, and 8 months) participated. Forty-eight Ss received an audiovisual stimulus contingent on arm movement, and 32 infants did not control the stimulus. Infant facial expressions during learning and extinction were coded using the Maximally Discriminative Facial Movement Coding System (MAX). Infants in the contingent group expressed greater interest and joy during learning and greater anger during extinction. There was a high concordance between arm pulling and the expression of anger during extinction, indicating that a brief exposure to extinction produces frustration-like changes in emotional responsivity. Individual differences existed in infant responses to frustration during extinction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)