This document discusses social-emotional development in infants. It explains that infants' temperament and ability to interact with others is shaped by how much they are held, cuddled and talked to. Erik Erikson's stages of psychosocial development are also summarized, noting that trust is the first stage and is achieved through consistency and having basic needs met promptly. The document also outlines how bonding and attachment form between parents and infants in the first year. Infants explore their world through play and start developing emotions like love, fear and anger by 2 months old. Separation anxiety and infant rage are also explained.