Infant Temperament Types According to a study by Alexander Thomas, Stella Chess, and colleagues there are three broad temperament categories that infants can be classified in; easy babies, difficult babies, and slow-to-warm-up babies. The characteristics of easy babies are that they are playful, positive mood, regular in biological functions and adapt readily to new circumstances. Difficult babies are irritable, irregular in biological functions, and react intensely and negatively to new situations or try to withdraw from them. Slow-to-warm-up babies are low in activity level and their responses are typically mild. They require more time than easy babies to adapt to change (Lightfoot, Cole, & Cole, 2013). I have four children who are all
