Laughter in young children.

Research studies of laughter in children are reviewed, and a model describing eliciting conditions for laughter and related behavior is described. Following Spencer (1860), Berlyne (I960), and others, it is proposed that laughter occurs after conditions of heightened tension or arousal when at the same time there is a judgment that the situation is safe or inconsequential. The special case of laughter to discrepant or incongruous stimulation is described in detail, and it is suggested that laughter serves the function of signaling to a caretaker that a given stimulus is within the childs tolerable limits of arousal. In his 1969 review of laughter, humor, and play, Berlyne asks whether there could be any selective advantage to the organism who laughs, or whether this activity is as biologically superfluous as it seems. To the developmental psychologist this is an intriguing question; taking a biological view of developmental processes has often been helpful in understanding the behavior of the child (e.g., Bowlby, 1969). At the same time, examining such behaviors as laughter in the child may lead to generalizations impossible to discern in the more complicated laughter of adults or the rare laughter of primates. The present paper reviews selected studies of laughter in young children, exploring laughters possible adaptive value and elaborating Berlynes arousal model of laughter to describe eliciting conditions for laughter and related emotions. OBSERVATIONS OF INFANT LAUGHTER In human infants, laughter is not observed during the first weeks of life and usually follows infant smiling by at least 1 month. Wolff (1963) made systematic observations of eight infants during the first weeks after birth, observing both spontaneous and elicited smiling (to auditory stimulation) in infants within