Preference for novel faces in male infant monkeys predicts cerebrospinal fluid oxytocin concentrations later in life

Abstract

The ability to recognize individuals is a critical skill acquired early in life for group living species. In primates, individual recognition occurs predominantly through face discrimination. Despite the essential adaptive value of this ability, robust individual differences in conspecific face recognition exist, yet its associated biology remains unknown. Although pharmacological administration of oxytocin has implicated this neuropeptide in face perception and social memory, no prior research has tested the relationship between individual differences in face recognition and endogenous oxytocin concentrations. Here we show in a male rhesus monkey cohort (N = 60) that infant performance in a task used to determine face recognition ability (specifically, the ability of animals to show a preference for a novel face) robustly predicts cerebrospinal fluid, but not blood, oxytocin concentrations up to five years after behavioural assessment. These results argue that central oxytocin biology may be related to individual face perceptual abilities necessary for group living, and that these differences are stable traits.

Figure 1

Infant preference for novel faces and later measures of oxytocin (OT) biology. (a) Individual variation in visual preference for novel faces. The box-and-whisker plot shows the interquartile range and median (box), and the 10^th and 90^th percentiles (whiskers), and remaining outliers. (b) Early preference for novel faces predicts later cerebrospinal fluid (CSF) OT concentrations (P = 0.0048). CSF OT concentrations are corrected to reflect the Weighted Least Squares General Linear Model (WLS-GLM) analysis, and are thus plotted as the expected value for each data point, plus the weighted residual. (c) Preference for novel faces does not predict later plasma OT concentrations (P = 0.2138); as before, the y axis values (plasma OT level) are corrected. (d) Plasma OT concentrations do not predict CSF OT concentrations (P = 0.8674), as before the y axis (CSF OT level) is corrected. In panels (b,c, & d), the line depicts the expected values for each data point from the WLS-GLM regression equation.