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Compared performance of preschool children, chimpanzees, and orangutans on nonverbal task of false-belief understanding and tested children's performance on a verbal version of the same task. Found that children's performance on verbal and nonverbal tasks were highly correlated, and no chimp or orangutan succeeded in the nonverbal false-belief task even though they evidenced mastery of general task demands. (Author/KB)

Infant abuse and neglect were investigated in five families of group-living pigtail macaques over five generations. Neglect was mostly limited to first-born and newborns; closely related rather than distantly related females were more prone to abuse; and infants with siblings previously abused were at highest risk. Results provide evidence of family abuse patterns in nonhuman primates. (Author/DB)

Compared comprehension of novel communicative signs to assist 2.5- and 3-year-old humans, chimpanzees, and orangutans find hidden objects during a hiding-finding game. Found that children at both ages performed above chance with all signs. No ape performed above chance for any signs not known before the experiment despite three times as many trials as the children. (Author)

The social development of a female rhesus monkey was followed from birth until death, age 32 months. The monkey had an extra autosome and was hydrocephalic. The monkey showed serious motor deficiencies, delayed social development, poorly established dominance relationships, and heavy dependence on mother and kin. The monkey was, however, well integrated into the social group. (Author/DB)

Research on humans and monkeys is reviewed that supports the view that the medial temporal lobe, and, perhaps more specifically the amygdala, is the neural substrate underlying social deficits in autism. The relationship of early medial temporal lobe lesions to memory and socioemotional behavior is reviewed, as are the roles of the amygdala and the hippocampus. (DB)

Comparison of social choices of trisomic macaques and of control groups found that groups showed few differences in preferences for stimulus animals with and without disabilities. Results suggest that the avoidance of individuals with disabilities is not a general primate trait and the presence of mental retardation and physical handicaps need not reduce positive social motivation. (Author/DB)

Through analysis of chimpanzee-human discourse, study shows that four chimpanzees exposed to humanly devised symbol system use partial or complete repetition of others' symbols. They do not produce rote imitations but use repetition to fulfill variety of pragmatic functions in discourse. Theories are advanced regarding meaning of two differences that appeared in use of repetition and length of utterances. (KM)

Judgments of similarity among mammals, including humans, were elicited from 7 and 10 year olds and adults. Results partially supported a consensus model of shared cultural knowledge. Patterns of deviation from the model appeared between children and adults because of the emergence of a primate category after age 10. (BC)

In a study of interspecies understanding, 75 naive human listeners classified 18 vocalizations of monkeys into 1 of 7 semantic categories, which were also related to the behavioral situation. Results suggest that both species share vocalization patterns signalling fear, aggression, dominance, and emotional neutrality. (45 references) (LB)

Describes two studies involving chimpanzee mother-infant pairs in Tanzania between 1980 and 1987 that implemented control theory concepts. The first identified behavioral development in infant chimps; the second observed the growth of independence and parenting patterns. Concludes that the hierarchy of controlled variables develops consecutively during growth from birth to maturity. (CH)

Scientists doing research on primates are increasingly being subjected to threats and acts of violence from animal rights groups. The intimidation has resulted in many laboratories taking extensive security measures. Some scientists claim, however, that there is no surrogate for animal research in understanding human diseases. There are fears that younger researchers will avoid primate research due to safety concerns. (DB)

A human demonstrator showed human children and captive chimpanzees how to drag food or toys closer using a rakelike tool. One side of the rake was less efficient than the other for dragging. Chimps tried to reproduce results rather than methods while children imitated and used the more efficient rake side. Concludes that imitation leads to accumulation of knowledge. (PVD)

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 at coping. (RH)

Presents studies on primates and human infants suggesting that maternal depression may predispose the infant to chronic depression. Findings also suggest that the effect of early separations from the mother may provide a model for reactive depression in the infant. (Author/BB)

Presents information about primates, including definitions and examples. Includes the activities "Thumbless Relay" and "Face It," which relate attributes of primates. Includes a story about chimpanzees along with discussion questions about the story. Reproducible worksheets and a quiz are also provided. (TW)

This article attempts to illustrate the value of a psychobiological approach to the study of a particular behavior; in this case, vocalization of infant primates following loss of the mother. (PCB)

Capacity of infant monkeys to mount an antibody response to viral challenge was evaluated after monkeys' removal from their mothers in several social and physical environments. Results indicated that trauma of separation was reduced when infants were familiar with the separation environment or familiar social companions were available. (PCB)

Study looks at pigtailed macaque in the context of visual recognition problems adapted from a standardized test developed for use with human infants. Results demonstrate that the low-risk group easily differentiated novel from previously seen targets; the high-risk group gave no evidence of recognition. (Author/RWB)

Four studies involving 40 pigtail monkeys are described in which relatively short separation experiences in infancy were associated with evidence of persistent changes in social behavioral function (less sociability, fewer close friends) and immunological function (suppression of lymphocyte proliferation) up to 6 years later. (Author/JDD)

Provides an overview of basic and applied studies for which primates are appropriate subjects. Summarizes the advantages, limitations, and constraints of using nonhuman primates in research. (RT)