Harlow's Monkeys and Contact Comfort

All 7 Terms & Definitions

Contact comfort

The tactile, physical sensation of clinging to a soft, warm surface — identified by Harlow as the primary determinant of infant attachment behaviour in rhesus macaques. Harlow's infants consistently chose the cloth mother over the wire mother regardless of which provided milk, demonstrating that the evolutionary function of attachment is not hunger reduction but proximity and physical contact with a protective figure. Contact comfort as a primary drive challenged decades of behaviourist and psychoanalytic theorising about the primacy of feeding in attachment formation.

Secure base

An attachment figure from whom an infant explores outward and to whom they return when threatened or uncertain, using the figure to regulate distress and restore security. Harlow's infant monkeys showed precisely this pattern with the cloth mother: they explored a novel environment from the cloth mother as a base, returned to her when frightened, and used contact with her to calm before venturing out again. Monkeys with only wire mothers showed no secure base behaviour. Bowlby developed this concept theoretically; Ainsworth later operationalised it in the Strange Situation procedure.

Critical period and early deprivation

Harlow's isolation studies revealed that early social experience is not merely helpful but necessary for normal social and emotional development. Monkeys raised in total social isolation for 6 months or more showed severe and apparently permanent deficits: they could not engage in normal social interaction, failed to mate, were unable to parent their offspring, and showed stereotyped self-harming behaviours (rocking, self-clasping). The severity of deficits depended on duration and completeness of isolation, suggesting a sensitive or critical period in early development during which social contact is essential.

The "cupboard love" theory and its refutation

The behaviourist account (drive-reduction theory) held that infants become attached to mothers because the mother, through feeding, reduces the hunger drive and becomes a conditioned reinforcer. The Freudian account similarly emphasised the oral stage and the breast as the primary source of both nourishment and libidinal attachment. Harlow's wire/cloth mother experiment was a direct, controlled refutation of both: when food and contact comfort were separated, infants consistently chose contact comfort — demonstrating that feeding is insufficient to establish primary attachment.

Bowlby's attachment theory

Developed in parallel with Harlow's empirical work, John Bowlby's attachment theory proposed that infant-caregiver attachment is a primary biological drive that evolved to maintain proximity to a protective adult — serving survival rather than hunger reduction. The theory drew on ethology (Lorenz's imprinting in geese), evolutionary biology, and clinical observation. Harlow's experiments provided the first controlled animal evidence for Bowlby's core claim that contact and proximity — not feeding — drive attachment, and the two scientists acknowledged each other's contributions as mutually reinforcing.

Motherless mothers

A troubling outcome of Harlow's deprivation studies: female monkeys raised without mothers or normal social contact consistently failed to parent their own offspring adequately. These "motherless mothers" typically ignored, neglected, or actively abused their infants — unlike normally reared mothers. The finding demonstrated that adequate early social experience is necessary not only for individual well-being but for the transmission of appropriate caregiving behaviour to the next generation — with implications for intergenerational cycles of deprivation in both animal and human populations.

Ethical concerns and animal welfare reform

Harlow's isolation experiments — particularly the "pit of despair" devices designed to induce depression-like states — caused deliberate, severe, and often lasting psychological harm to infant monkeys. These studies are among the most ethically contested in the history of animal research. They contributed substantially to reform of animal research ethics: the US Animal Welfare Act and institutional animal care guidelines were strengthened partly in response to public reaction to isolation research. No current institutional ethics board would sanction the total isolation procedures used in Harlow's 1960s studies.