Harry F. Harlow

Maternal separation in the rhesus monkey.

MATERNAL SEPARATION IN THE RHESUS MONKEY BILL SEAY;HARRY HARLOW; The Journal of Nervous and Mental Disease

Age-Mate or Peer Affectional System

Publisher Summary This chapter discusses the age-mate or peer affectional system. The most pervading and important of all the affectional systems in terms of long-range personal-social adjustment is the age-mate or peer affectional system. This system begins through interaction between infants and children and continues throughout preadolescence, adolescence, and adulthood. Age-mate or peer affectional relationships may exist between members of the same sex or members of opposite sexes, but there are certain basic physical and behavioral differences conducive to sexual separation insofar as the age-mate affectional system is concerned. The age-mate affectional system begins when the intimate physical bonds between the mother and child weaken and the infant is permitted to wander beyond the range of the maternal body and maternal arms. The separation is normally as much or more a function of the infants behavior as it is a function of changes by the mother. The chapter discusses the developmental stages, including the (1) stages of intimate object play, and (2) stages of age-mate affection. The age-mate affectional variables are also reviewed in the chapter.

Induced depression in monkeys

Recent work at the Wisconsin Primate Laboratory has been directed toward experimental production and cure of human-type psychopathologies in rhesus monkey subjects. A primary emphasis has been on depression. Data are presented which identify different procedures designed to produce depression, help determine the susceptibility of any given subject to such procedures, and which outline methods and modes of therapy. The significance and future of work in the area of monkey models of human disorders is discussed.

Monkeys (Macaca mulatta) raised only with peers. A pilot study

Abstract Four infant rhesus raised in a group (4-TT) and six raised in pairs (2-TT) were compared with eight infants raised on mother surrogates (SP) and twenty raised with real mothers (MP). When tested with peers early in life 4-TT and 2-TT subjects showed less play, hostility and sex, and the 2-TT subjects exhibited a preponderance of social cling. When tested as adults the 2-TT and 4-TT monkeys were below controls on measures of play, above controls on social proximity, hostility, and withdrawal, and the 2-TT subjects showed inadequate sexual adjustment. Data are interpreted as suggesting that behaviours normally associated with affectional ties can become so extreme as to inhibit normal social development.

Long-Term Effects of Total Social Isolation Upon Behavior of Rhesus Monkeys:

8 isolate monkeys were compared in a follow-up study to 8 sophisticated controls in brief cross-sectional pairings with 12 stimulus strangers: 4 adults, 4 age-mates, and 4 juveniles. The isolates were characterized by infantile disturbance, less environmental orality, more fear, more aggression, less sex, less play, and bizarre ritualistic movements. 12-mo. isolates were fearful and nonaggressive but threatened many attacks. 6-mo. isolates were fearful and physically aggressive. The 12-mo. isolates demonstrated practically no positive social behavior. Conclusions are: (a) 6 mo. of social isolation during the first year has negative effects on social behavior up to puberty, (b) abnormal aggression appears in 3-yr.-old 6-mo. isolates, and (c) 12 mo. of isolation suppress or delay this aggression.

Learned Behavior of Rhesus Monkeys following Neonatal Bilateral Prefrontal Lobotomy

Bilateral ablation of dorsolateral frontal cortex in the newborn animal failed to produce the frontal lobe syndrome typical of the adolescent and adult stages. The crucial tests (delayed response, string tests, and discrimination learning) were performed 3 to 4 months postoperatively. At this time, no significant differences between normal animals and animals with prefrontal lesions were found.

EFFECTS OF THREE MONTHS OF TOTAL SOCIAL DEPRIVATION ON SOCIAL ADJUSTMENT AND LEARNING IN THE RHESUS MONKEY

Rhesus monkeys reared in total social isolation for the first 3 months of life were compared with 3-month partial social isolates on social and learning behaviors. Home-cage observations also were taken over the isolation and social testing periods. The 3-month total social isolates showed extreme withdrawal when they were removed from the isolation chambers, and this withdrawal was so severe that one S died of starvation because it refused to eat food placed in its cage. The totally socially isolated Ss exhibited a drop in oral and manual exploration of the cage when removed from isolation and showed an increase in the category of self-directed orality. The isolates also showed difficulty in adapting to new situations. However, no differences in social or learning behaviors were found between the 3-month total social isolates and their partially socially isolated controls.

Approach-Avoidance Conflict in the Mother-Surrogate Situation

The theoretical formulations of Miller ( 1959) on approach-withdrawal conflict behavior in animals have been based primarily on situations involving the counterposing of a secondary drive of fear, frequently based upon the aversive stimulation of shock, and an appetitive drive of either hunger or thirst. It has been suggested that in such siruations if the aversive stimulus is presented in the same locus as the positive reinforcement, conflict behavior in the form of hesitation and vacillation will occur increasingly further from the locus of positive reinforcement as a function of the intensity of the aversive stimulus. The general effect of this conflict behavior is to decrease the probability of responsiveness to the positive reward position. The affectional responsiveness of infant rhesus monkeys to artificial mother surrogates measured in the time spent in contact with the surrogace (Harlow & Zimmermann, 1959) represents a strong adient response somewhat different in character from that for food or water. It is the purpose of the present paper to present data resulting from the systematic introduction of an aversive stimulus associated with response to the artificial surrogate during the development of the affectional pattern.

Reversal of social deficits produced by isolation rearing in monkeys

Abstract A major body of research has clearly demonstrated that rearing monkeys for at least the first 6 months of life in total social isolation from conspecifics produces profound psychopathology, including both massive social deficits and ideosyncratic self-directed behaviors rarely seen in normal monkeys. Previously, isolation-induced psychopathology was thought to be permanent, and various theoretical explanations, e.g. critical periods and “emergence trauma” were posited to account for such phenomena. Recent research at Wisconsin has indicated that the isolation syndrome in monkeys is, in fact, reversible, rendering the above theoretical positions inadequate. In this paper, the procedures for successful rehabilitation of isolate-reared monkeys are described and an alternative theoretical explanation presented. Implications of the theory and data are discussed.

Sex differences in the infant-directed behavior of preadolescent rhesus monkeys.

15 pairs of preadolescent rhesus monkeys matched for rearing experience were tested with a 1-month-old infant. Preadolescent females directed significantly more positive social behavior (p < .05) and significantly less hostility (p < .01) toward the infant than did males. These results are taken as evidence that hormonal changes at puberty are not the only variables producing sex differences in infant-directed behavior.