Social cognitive and physiological aspects of humour perception from 4 to 8 months: Two longitudinal studies

摘要

Infants laugh by 4 months, but whether they understand humour based on social or cognitive factors is unclear. We conducted two longitudinal studies of 4-, 6-, and 8-month-olds (N = 60), and 5-, 6-, and 7-month-olds (N = 53) to pinpoint the onset of independent humour perception and determine when social and cognitive factors are most salient. Infants were shown six events in randomized repeated-measures designs: two ordinary events and two absurd iterations of those events, with parents’ affect manipulated (laugh or neutral) during the latter. Four-month-olds did not smile/laugh more at absurd events, but exhibited a significant heart rate deceleration. Five-month-olds independently appraised absurd events as humorous, smiling/laughing despite their parents’ neutrality. Parent laughter did not influence infants of any age to smile more, but captured 4-month-olds’ attention. Results suggest that 4-month-olds laugh in response to social cues, while 5-month-olds’ can laugh in response to cognitive features.