Temperament and play interaction behavior across infancy

Temporal stability and convergent validity of infant temperament ratings and play interaction behaviors were examined across early to late infancy. Stability was noted for the temperament dimensions activity, rhythmicity, intensity, mood, and persistence. Stability also was noted for the infant play interaction behaviors looking, smiling, and vocalizing. In addition, convergent validity was noted for attentive-affective behaviors and comparable temperament ratings; for example, gaze aversion and nondistractability, and distress brow behavior and negative mood. Generally easier temperament infants were noted to vocalize more and to cry less frequently during their play interactions.