Eight stump-tailed macaques were reared individually and either given all of their daily social experience in darkness or given half in the dark and half in the light. Results suggest that vision is especially important in the maintenance of assertive behaviors and in the instigation and direction of aggressive behaviors. (Author/RH)

Four-month-old rhesus monkeys were removed from their social group under three different conditions of perceptual isolation from their mothers and peers. Infant behavior was recorded and blood samples were obtained for analysis of plasma cortisol. Infants never showed signs of depression; their responses following separation were seen as attempts…

Key components of human behavioral genetics and Sandra Scarr's work of the past two decades are critically reviewed based on scholarship in animal neuropsychology and clinical and educational psychology. Scarr's opinion that interventions to enhance intellectual development are ineffectual for children from abuse- and neglect-free backgrounds is…