Hamlin et al . found in 2007 that preverbal infants displayed a preference for helpers over hinderers. The robustness of this finding and the conditions under which infant sociomoral evaluation can be elicited has since been debated. Here, we conducted a replication of the original study, in which we tested 14- to 16-month-olds using a familiarization procedure with three-dimensional animated video stimuli. Unlike previous replication attempts, ours uniquely benefited from detailed procedural advice by Hamlin. In contrast with the original results, only 16 out of 32 infants (50%) in our study reached for the helper; thus, we were not able to replicate the findings. A possible reason for this failure is that infants' preference for prosocial agents may not be reliably elicited with the procedure and stimuli adopted. Alternatively, the effect size of infants’ preference may be smaller than originally estimated. The study addresses ongoing methodological debates on the replicability of influential findings in infant cognition.

No abstract

Evaluating others’ actions as praiseworthy or blameworthy is a fundamental aspect of human nature. A seminal study published in 2007 suggested that the ability to form social evaluations based on third-party interactions emerges within the first year of life, considerably earlier than previously thought (Hamlin, Wynn, & Bloom, 2007). In this study, infants demonstrated a preference for a character (i.e., a shape with eyes) who helped, over one who hindered, another character who tried but failed to climb a hill. This study sparked a new line of inquiry into infants’ social evaluations; however, numerous attempts to replicate the original findings yielded mixed results, with some reporting effects not reliably different from chance. These failed replications point to at least two possibilities: (1) the original study may have overestimated the true effect size of infants’ preference for helpers, or (2) key methodological or contextual differences from the original study may have compromised the replication attempts. Here we present a pre-registered, closely coordinated, multi-laboratory, standardized study aimed at replicating the helping/hindering finding using a well-controlled video version of the hill show. We intended to (1) provide a precise estimate of the true effect size of infants’ preference for helpers over hinderers, and (2) determine the degree to which infants’ preferences are based on social features of the Helper/Hinderer scenarios. XYZ labs participated in the study yielding a total sample size of XYZ infants between the ages of 5.5 and 10.5 months. Brief summary of results will be added after data collection.

Despite the numerous findings on the sophisticated inferences that human infants draw from observed third-party helping interactions, currently there is no theoretical account of how they come to understand such events in the first place. After reviewing the available evidence in infants, we describe an account of how human adults understand helping actions. According to this mature concept, helping is a second-order goal-directed action aiming to increase the utility of another agent (the helpee) via reducing the cost, or increasing the reward, of the helpee’s own goal-directed action. We then identify the cognitive prerequisites for conceiving helping this way and ask whether these are available to infants in the interpretation of helping interactions. In contrast to the mature concept, we offer two simpler alternatives that may underlie the early understanding of helping actions: (i) helping as enabling, which requires second-order goal attribution but no utility calculus, and (ii) helping as joint action, which requires efficiency (i.e., utility) evaluation without demanding second-order goal attribution. We evaluate the evidence supporting these accounts, derive unique predictions from them, and describe what developmental pathway towards the mature concept they envisage. We conclude the article by outlining further open questions that the developmental literature on the interpretation of helping interactions has not yet addressed.

Null Hypothesis Significance Testing is a statistical procedure widely used in cognitive development research. There is widespread concern that the results of this statistical procedure are misinterpreted and lead to unsubstantiated claims about studies’ outcomes. Two particularly pertinent issues for research on cognitive development are: i) treating a non-significant result as evidence of no difference or no effect, and ii) treating a non-significant result in one group/condition and a significant result in another as evidence of a difference between groups/conditions. The current study focuses on quantifying the extent to which these two issues can be observed in the published literature on cognitive development. To this end, we will systematically search for empirical studies investigating cognitive development in 0-to-16-year-old children that have been published at two time points, namely in 1999 and 2019. For each of the two issues, we will extract information from 300 published articles, 150 per publication year.