Infant perception of sex differences in biological motion displays

Abstract

We examined mechanisms underlying infants' ability to categorize human biological motion stimuli from sex-typed walk motions, focusing on how visual attention to dynamic information in point-light displays (PLDs) contributes to infants' social category formation. We tested for categorization of PLDs produced by women and men by habituating infants to a series of female or male walk motions and then recording posthabituation preferences for new PLDs from the familiar or novel category (Experiment 1). We also tested for intrinsic preferences for female or male walk motions (Experiment 2). We found that infant boys were better able to categorize PLDs than were girls and that male PLDs were preferred overall. Neither of these effects was found to change with development across the observed age range (∼4-18 months). We conclude that infants' categorization of walk motions in PLDs is constrained by intrinsic preferences for higher motion speeds and higher spans of motion and, relatedly, by differences in walk motions produced by men and women.

Untangling the Ties Between Social Cognition and Body Motion: Gender Impact

“…This outcome appears to dovetail with recent reports indicating that females and males tend to use different types of information during BM processing and gender recognition in point-light displays: females rely on form and motion cues together, whereas males use motion cues solely (Hiris et al, 2018). This is also in line with recent findings on gender recognition in human infants aged 4-18 months: in a habituation paradigm, boys more easily differentiate the gender of a pointlight walker, presumably possessing higher sensitivity to motion parameters (Murray et al, 2018;Tsang et al, 2018). Yet adaptation effects in point-light BM gender recognition indicate that this process is rather unlikely to be based on extracting low-level perceptual features (Jordan et al, 2006).…”

Infants' identification of gender in biological motion displays

“…We first analyze data aggregated across the familiarization and test phases of the three experiments to test for a male PLD preference (cf. Tsang, Ogren, et al, 2018). Next, we analyze for gender matching at test in each experiment, followed by analyses of relations between individual differences in F I G U R E 2 Female (left in this example) and male (right) PLDs were viewed as a female or male voice was heard (Experiments 1 and 2).…”

“…Recently, Tsang, Ogren, et al (2018) reported results from two experiments that shed light on infants' perception of gender in PLDs. In the first experiment, Tsang et al asked whether infants would show a preference for female (vs. male) PLDs, as they do for female (vs. male) faces (Quinn et al, 2002) and perhaps voices (Decasper & Prescott, 1984;Spence & Freeman, 1996; but see Werker & McLeod, 1989).…”

“…In a second experiment, Tsang, Ogren, et al (2018) asked whether infants would categorize PLDs according to gender, as they do for female versus male faces (Ramsey et al, 2005). Categorization is a fundamental cognitive activity that guides the grouping of objects and events by organizing lowlevel structure and more abstract relations (Mervis & Pani, 1980), and in adults, social categorization appears to be an obligatory aspect of social life (Allport, 1954).…”

“…Notably, categorization in the Tsang, Ogren, et al (2018) study was facilitated by attention to PLDs' upper regions. As noted, these upper regions are particularly diagnostic for determining gender differences because men's shoulders and arms undergo greater translatory motion than women's when walking (Troje, 2002;.…”