Nonverbal face‐to‐face interactions in macaques and humans: A translational pilot study

Abstract

AbstractHuman and nonhuman primate mother–infant dyads engage in face‐to‐face interactions critical for optimal infant development. In semi‐free‐ranging rhesus macaques (Macaca mulatta), maternal primiparity and infant sex influence the expression of nonverbal face‐to‐face mother–infant interactions. However, whether similar patterns of variation exist in laboratory‐housed macaques or human mothers is not well understood. Comparing both species would yield information regarding the translational validity of macaques to humans in this important social/developmental domain. In this pilot study, we first compared semi‐free‐ranging (n = 39) and laboratory‐housed (n = 20) macaques, finding that laboratory‐housed dyads, first‐time mothers, and mothers of sons engaged in higher rates of face‐to‐face interactions regardless of housing. After translating the nonhuman primate coding scheme for use in a small but diverse group of human mother–infant dyads (N = 27; 44.4% African American, 18.5% American Indian, 7.4% Asian/Asian American, and 29.6% White), we found that, like macaques, human mothers of sons engaged in more face‐to‐face interactions; however, experienced (vs. first‐time) mothers engaged in more interactions. Macaques and humans also engaged in species–specific interactions with their infants. We conclude that components of caregiver–infant nonverbal face‐to‐face interactions are translatable across human and nonhuman primate species and represent an exciting avenue for future caregiving work.