"Attachment Bonds and Behavior in Free-Ranging Male Infant Rhesus Monkeys: Species-Typical Patterns and Individual Differences in Secure Base Use and Security" by James J. Warfield

James J. Warfield

Deposited 2003

Abstract
This study evaluated free-ranging male infant rhesus monkey species-typical (normative) attachment behavior, measured individual differences in attachment security, and evaluated the effects of those differences on risk assessment and social competences.

Twenty-three free-ranging rhesus monkey male infants living in naturalistic conditions at Cayo Santiago PR were sampled for more than 200 behaviors thrice weekly from birth through 10 months of age. Subjects were also videotaped for two half-hours every 6 weeks; videotapes were used to score attachment security with a 94-item Secure Base Q-Sort (SBQS-RM) developed for free-ranging infant rhesus monkeys emphasizing attachment/exploration balance. A scale consisting of four quantitative variables (SBSS) derived from the SBQS-RM also measured attachment security effectively.

Infants used mothers as primary secure bases through the entire 10 months they were observed. Most infants used other monkeys as a secure base occasionally, but not after 8 months of age; no infant developed an attachment bond with any monkey other than its mother (indexed by distress vocalizations on separation, sleeping partners, nipple contact).

After 3 months of age, infants self-scratched significantly less in contact with their mothers and more in arm's length of her than at other distances, a pattern best explained by an approach-avoid conflict with contact as the infant's goal and non-contact as the mother's goal. Infants gave significantly more distress calls within arm's length of their mothers. Although self-scratching and distress vocalization rates suggest that subjects were discomfited in arm's length of their mothers, they maintained a strong preference for being in contact or close proximity to their mothers, even though as infants' needs for protection and nutrition increased after 3 months of age their mothers provided less protection and less nutrition, if any.

Time spent in social play varied widely among individuals, was not associated with attachment security, risk assessment, or social competence, was higher among infants of primiparous mothers, in larger groups, and among infants spending more time than other infants beyond 3m from mothers.

Attachment bonds played an important role in infant social behavior; individual differences in attachment security were complexly associated with risk assessment, social competence, and maternal spacing.