Use of Repeated Within-Subject Measures to Assess Infants’ Preference for Similar Others

Abstract

Research employing single-choice paradigms in which an infant is asked to make a single choice between two puppets suggest that infants show a preference for prosocial others and those who are similar to themselves. However, the extent to which infants’ preference for similar others is stable is unknown, as are other factors within the paradigm that may influence infants’ choices. The purpose of this study (two experiments, N = 44 infants, aged 8–15 months) was to replicate and extend previous work by including (1) within-subject repeated measures and (2) an experimental manipulation of a plausible demand characteristic. Results for the first-choice trial indicated a majority of the infants did not choose the similar puppet. Results from the within-subject repeated trials also indicated that a majority of the infants did not choose the similar puppet but a majority did choose a puppet from the same side. The experimental manipulation of the demand characteristic showed no effect on infant puppet choices. These results suggest that a closer examination of the single-choice puppet paradigm for assessing infants’ social evaluation is warranted. These findings also support recommendations made by others, including publishing null findings, standardizing data collection and reporting methods, and examining individual differences by employing within-subject designs with repeated measures.

Understanding preferences in infancy

“…Therefore, as infants navigate the social world, not only do they form their preferences in toys, foods, or even people, with or without others' influences, they also come to compare their own with others' preferences and use this information to guide their interactions with them. Infant favoritism toward similar others (i.e., those with shared preferences or certain ingroups) and their preferences for prosocial agents (although for a non‐replication report, see Cruz‐Khalili et al, 2019) are similar to adult social perceptions, at least to some extent (Ambady & Rosenthal, 1992; Brewer, 1999; Winter & Uleman, 1984). These early social preferences are consistent with the view that infants hold early emerging expectations about being helpful and supportive toward similar others, or ingroup members (“ingroup support,” Bian & Baillargeon, 2022; Ting et al, 2020).…”

Simplicity and validity in infant research

“…This more general tension between measurement and ecological validity is perhaps most prominent in the methods commonly used for exploring infants' cognitive capacities: measures of infants' relative looking time or preferential reaching (e.g., Schmuckler, 2001). In these, how long infants look at certain stimuli (e.g., Colombo & Mitchell, 2009;Rankin et al, 2009;Cruz-Khalili et al, 2019), or whether they reach for one stimulus or another in response to previous observations (e.g., Feigenson, Carey, & Spelke, 2002;Hamlin et al, 2007) is taken to be a measure of various cognitive processes. Given there are often multiple ways to interpret these -rather generic --looking and reaching behaviors, their use brings interpretation challenges.…”