Infant humor perception from 3- to 6-months and attachment at one year

Infancy is a critical time for the development of secure attachment, which is facilitated by emotionally synchronous interactions with parents. Humor development, which includes shared laughter and joint attention to an event, emerges concurrently with attachment, but little is known regarding the relationship, if any, between humor development and attachment in the first year. Thirty 3-month-old infants were videoed at home each month until they were 6-months old while their parents attempted to amuse them. Frequency of infants’ smiles and laughs served as a measure of “state humor”, and the smiling/laughing subscale of the Infant Behavior Questionnaire-Revised served as a measure of “trait humor”. State and trait humor were not correlated. Lower trait humor as 6 months predicted higher attachment security on the Attachment Q-sort at 12-months (r = .46), suggesting that less good-humored infants elicit greater parental engagement, which works to the benefit of attachment, or vice versa. Future studies should examine the importance of smiling and laughter as they relate to other developmental phenomena in the first year.

► State and trait humor were not correlated in 6-month old infants, suggesting these are separate dimensions of the same construct as has been found with adults.
► Only trait humor at 6-months predicted attachment security at one year.
► The inverse relationship between trait humor and attachment security suggests that parents of less good-humored infants may work harder to emotionally engage their infants, which may favor attachment security.