Difficult Temperament

Difficult temperament is one of three broad temperament categories identified by the psychiatrists Alexander Thomas and Stella Chess through their New York Longitudinal Study, a landmark project following the same children from infancy that they began in 1956, describing infants who show irregular biological rhythms, such as unpredictable sleeping and feeding schedules, slow and effortful adaptation to new situations or changes in routine, frequent expression of negative mood, and intense, often prolonged emotional reactions to both positive and negative events. In Thomas and Chess's original sample, infants classified with difficult temperament made up a smaller group, roughly ten percent of the children studied, and this pattern was found to make caregiving considerably more demanding, since these infants tend to react strongly and negatively to new experiences, resist changes in established routines, and can be harder for caregivers to soothe once distressed. Thomas and Chess found that infants with difficult temperament faced a somewhat elevated risk of later behavioral problems compared with infants classified as easy, but crucially found this outcome was far from automatic, since the eventual result depended heavily on the surrounding caregiving environment: caregivers who responded to a difficult temperament with patience, consistency, and a willingness to adapt their own expectations tended to see the child adjust well over time, while caregivers who responded with frustration, rigidity, or punitive discipline tended to see difficulties compound, illustrating the broader goodness-of-fit principle at the center of Thomas and Chess's overall temperament research.