Human Development · Chapter 6

Temperament & Goodness of Fit

Some babies are sunny and unbothered; some are fussy and intense; some hang back before warming up. Psychiatrists Thomas & Chess tracked these patterns in their New York Longitudinal Study and named three temperament types. What shapes a child most isn't the type — it's the goodness of fit between the child and their world. Tap a type, then test a caregiving environment.

Pick a temperament

Three temperament typestap one to explore

Goodness of fit — test a caregiving environment

Goodness of fit (Thomas & Chess) — development goes best when caregiving matches the child's temperament. No type is simply "good" or "bad": the same difficult child can thrive with patient, predictable parenting yet struggle with harsh, rushed parenting. About 35% of infants don't fit neatly into any one type.