This Brief synthesizes findings from recent experiments on jealousy in infants with insights from pioneering thinkers in developmental science. It discusses attachment issues, status of jealousy as an emotion and as a feature of temperament, underpinnings in social cognition, the development of adaptive versus maladaptive presentations, and facets of jealousy that may be part of a normal repertoire of coping strategies. This unique volume also identifies facial, vocal, and bodily responses associated with jealousy as well as situations of differential treatment by caregivers that may bring...