The study, conducted by Zijian Tian and Kazuo Hiraki of the University of Tokyo, set out to answer a deceptively simple question: does a baby’s assessment of an act of sharing change depending on whether the baby is judging from the viewpoint of the person giving, the person receiving, or a neutral bystander? Decades of research have shown that preverbal infants prefer helpers over hinderers, fair distributors over unfair ones, and protectors over aggressors. But those findings typically tested infants as third-party observers watching scripted puppet shows. The Tokyo team suspected that when the moral stakes are personal—when the evaluator is imagined to be a participant in the interaction itself—the picture might look very different.

To find out, the researchers built an animated scenario around a swing. One agent, the initial possessor, arrives first and claims the swing, riding it upward with sparkling sound effects that mark the experience as rewarding. A second agent, a newcomer, then appears and jumps repeatedly while facing the swing and maintaining eye contact with its occupant—a behavior designed to signal a request for a turn. In the Sharing condition, the occupant dismounts and trades places, letting the newcomer ride. In the Non-sharing condition, the occupant turns back and keeps the swing. The design was deliberately chosen because a swing can be used by only one agent at a time, making it an ideal stand-in for a scarce, desirable resource whose repeated monopolization would be hard to depict with hills or slides.

The team then ran four eye-tracking experiments with a total of 103 infants, all around eleven months old and recruited from the University of Tokyo Baby Lab. The experiments crossed two manipulations. The first varied which agent stayed constant across the Sharing and Non-sharing events: in Condition A, the newcomer was the same green sphere-shaped character in both episodes, while in Condition B, the initial possessor was. The second manipulation varied the test phase: in Experiments 1a and 1b, a central agent—either the newcomer or the initial possessor—chose between two characters, and infants’ anticipatory gaze during a three-second window before the choice revealed whom they expected the agent to approach. In Experiments 2a and 2b, infants watched the two agents side by side as third-party observers, with a swing-seat ring lifting one agent upward to signal a positive outcome.

The results were strikingly asymmetric. In Experiment 1a, where infants predicted the choices of a newcomer requesting a turn, their anticipatory gaze lingered significantly longer on the agent who had shared the swing. The difference scores—fixation time on the sharing agent minus fixation time on the non-sharing agent—were significantly greater than zero during the first block of test trials, with a two-tailed test yielding p = 0.016 and a directional test p = 0.008. In plain terms, the babies expected the newcomer to prefer the character that had helped it get a turn. That preference vanished entirely in Experiment 1b, where infants instead predicted the choices of the initial possessor who had been asked to yield. There, difference scores did not deviate from zero in any trial block. And in both third-party experiments, 2a and 2b, no preference for the sharing agent emerged at all, either before or after familiarization.

Statistical modeling reinforced the pattern. Linear mixed-effects models fitted to the gaze data showed a significant main effect of trial repetition but no main effect of experiment, and post hoc comparisons confirmed that the sharing preference in Experiment 1a was confined to the earliest trials. Looking time after the choice was made—the classic violation-of-expectation measure—showed no systematic differences between conditions in any experiment, a limitation the authors attribute in part to the fixed five-second post-choice window, which may have been too brief to capture effects that infant-controlled paradigms typically allow to run longer.

Why would eleven-month-olds reward sharing only when judging from the newcomer’s side? The authors point to the asymmetry built into giving and taking. For the newcomer, the agent who yields the swing is unambiguously beneficial: it removes the obstacle standing between the newcomer and its goal. For the initial possessor, however, yielding means losing playtime on a resource it controls. Prior work has shown that infants use spatial position, body size, and group size to infer social dominance and expect dominant individuals to prevail rather than yield—so from the possessor’s vantage point, holding onto the swing may not register as a moral failing at all. And as neutral observers, infants may simply lack the motivational stake that makes either interpretation compelling.

The team also ruled out a battery of low-level perceptual explanations. If infants merely preferred whichever character was more novel or had spent less time on the swing, then Experiment 1b should have produced an even stronger preference for the newcomer who never got on the swing at all. It did not. Nor could recency or primacy effects explain the pattern, since the structural differences between the familiarization conditions across experiments controlled for those factors. The authors conclude that the infants’ looking preferences are best explained by the socio-moral structure of the taking-turns interaction itself—specifically, who gave and who received.

The findings carry implications well beyond the swing. If early moral preferences are this malleable, the field may need to rethink how it measures them. Rather than asking whether infants are prosocial, the authors argue, researchers should map when and under what criteria these evaluations emerge. Open questions remain: the study tested only eleven-month-olds raised in Japan in a laboratory setting, and the animated scenario isolated a single non-reciprocal episode in which the giver received no gratitude or social reward—unlike real life, where toddlers as young as sixteen months show more happiness when giving than keeping. Whether infants possess an abstract sense of possession that underpins their judgments also remains untested, though prior research shows preschoolers infer ownership from first arrival and control of permission.

What the study does establish is that the seeds of moral reasoning are planted earlier and grow in stranger shapes than the classic helper-hinderer experiments suggested. A baby not yet able to say a single word already understands that the same act—giving up a swing—can look generous from one side of the interaction and costly from the other. Perspective, it seems, is not a skill that develops later in childhood; it is woven into the very first moral judgments humans make.

Subject of Research: Perspective-dependent socio-moral evaluation of sharing behavior in preverbal infants

Article Title: Preverbal infants' evaluation of sharing behaviors within a “taking turns” context is modulated by the perspectives they adopt

Article References: Tian, Z., & Hiraki, K. (2026). Preverbal infants' evaluation of sharing behaviors within a “taking turns” context is modulated by the perspectives they adopt. Frontiers in Developmental Psychology, 4, Article 1904707. https://doi.org/10.3389/fdpys.2026.1904707

Image Credits: AI Generated

DOI: 10.3389/fdpys.2026.1904707

Keywords: infancy, socio-moral evaluation, perspective-taking, sharing, eye-tracking, developmental psychology, turn-taking, social dominance, fairness, resource distribution, preverbal infants, University of Tokyo

The research, conducted by Valentina Lucia La Rosa, Maria Luisa Indiana, Emanuela Borzì, Daniela Pirone, Elisabetta Sagone, Elena Commodari, and Alessandra Geraci at the University of Catania, builds on a well-established tradition in developmental psychology but adds a crucial cognitive twist. Earlier work had shown that children attribute fair and unfair distributions differently depending on the perceived gender of the distributor, yet comparatively little attention had been paid to the mental structures, known as schemas, that make such attributions possible. Gender schemas are organized knowledge structures that guide how children process, interpret, and remember gender-relevant information, and understanding when children first deploy them to encode social behavior is central to tracing the developmental origins of bias.

The team tested 160 typically developing children divided into four equal age groups: toddlers aged 2.5 years, preschoolers aged 3.8 years, kindergartners aged 5, and school-age children aged 8. Each child watched brief familiarization events in which a distributor, hidden behind a gray box, either gave one apple to each of two receivers, a cow and a pig, or handed both apples to a single receiver. Immediately afterward, the experimenter presented two schematic drawings, one male and one female, and asked the child to identify the distributor by picking up the correct picture. The position of the pictures was counterbalanced, the order of fair and unfair events was alternated across participants, and a manipulation check with 50 university students confirmed that the schematic figures were unambiguously recognized as male and female with 100 percent accuracy.

The results traced a non-linear developmental trajectory that surprised no one more than the researchers’ own carefully calibrated hypotheses. At 2.5 years, children chose the male and female figures at chance levels for both fair and unfair distributions, exactly as predicted by the literature on pictorial competence. Infants younger than three often treat pictures as objects to be touched and grasped rather than symbols that stand for something else, and the ability to hold both the physical properties of an image and its abstract referential meaning in mind simultaneously, what psychologists call dual representation, emerges only gradually. Without that symbolic foundation, the youngest participants simply could not map a schematic figure onto a real-world gender category, and their choices therefore revealed no gender-based pattern at all.

By 3.8 years, however, the picture changed dramatically. Seventy percent of children in this age group selected the male figure after watching a fair distribution, a statistically significant deviation from chance with a medium effect size, while their choices remained at chance after unfair events. This is the signature of what the researchers define as gender bias: a systematic tendency to attribute positive social behaviors preferentially to one’s own gender group, reflecting in-group favoritism without necessarily implying a negative evaluation of the out-group. The pattern was driven almost entirely by boys, 81.8 percent of whom attributed fair distributions to the male figure, while girls of the same age showed no significant tendency in either direction. According to Social Identity Development Theory, this asymmetry makes sense: in-group favoritism emerges as children consolidate a positive sense of group membership, and its strength depends on how salient and self-defining that group has become. For boys approaching their fourth birthday, gender may already function as a highly salient social category.

At age 5, the pattern flipped in a theoretically meaningful way. Children no longer associated the male figure with fair behavior; instead, 67.5 percent of them attributed unfair distributions to the male figure, again a significant departure from chance. This qualitative shift coincides with what decades of research identify as the developmental peak of gender stereotype rigidity, spanning roughly ages 5 to 7. During this window, children behave as what Martin and Ruble famously called gender detectives, diligently searching their environment for stereotype-consistent information and consolidating it into increasingly rigid expectations. Developmental Intergroup Theory predicts precisely this outcome: as gender becomes an ever more salient dimension of social life, children encode stereotype-consistent information with growing intensity, and here that intensity manifested as the association of men with dominant, inequitable behavior.

The most articulated pattern emerged among 8-year-old girls, who simultaneously attributed fair distributions to the female figure, at 71.4 percent, and unfair distributions to the male figure, at 78.6 percent. This combination of in-group favoritism and out-group negativity meets the study’s operational definition of gender prejudice, a qualitatively different construct from mere bias. Male 8-year-olds, by contrast, showed no significant gender-based pattern in either condition. The researchers suggest that girls at this age may have developed heightened sensitivity to gender-based social hierarchies, motivating a reactive intergroup stance in which protecting the in-group and devaluing the out-group become two sides of the same coin. Taken together, the findings sketch a trajectory in which boys display earlier but less differentiated in-group favoritism, while girls develop a later but more elaborated pattern that integrates group protection with out-group criticism.

The authors are careful to frame these results within a biosocial model rather than a simple nature-versus-nurture debate. An evolved sensitivity to group membership may provide the initial scaffold, but the direction of children’s attributions is unmistakably shaped by experience. From their earliest years, children observe that caregiving and daily resource allocation are unequally distributed across genders, and these accumulated observations likely feed the early association between the male figure and prosocial or dominant behavior. Crucially, the researchers emphasize that the attribution patterns observed here are not fixed developmental outcomes. Because they emerge from socialization, they remain modifiable: intervention research consistently shows that exposure to counter-stereotypical role models, such as female leaders and male caregivers in children’s stories, can attenuate gender bias even at preschool age.

The study does carry important boundary conditions. The sample consisted exclusively of White children from a single Italian region with limited socioeconomic diversity, so the observed patterns cannot be assumed to generalize to populations where gender norms and expectations about distributive fairness differ substantially. The use of highly schematic figures, while useful for isolating gender as the sole variable, reduces ecological validity, since real-world gender perception draws on a rich constellation of facial, vocal, and behavioral cues. Moreover, the forced-choice paradigm measures attribution behavior without directly observing the underlying schemas, and the authors call for future work pairing the task with independent assessments of gender schema knowledge, culturally diverse samples, longitudinal designs, and richer stimuli such as videos of dynamic social interactions.

Even with these caveats, the practical implications are difficult to overstate. The window in which gender schemas first begin to shape social reasoning opens before children turn four, long before formal schooling typically addresses equity in any systematic way. The findings argue for early childhood settings, nurseries, kindergartens, and caregiving environments, to actively promote counter-stereotypical representations of competence and fairness, particularly around resource sharing and leadership, rather than waiting for rigid prejudice to consolidate in middle childhood. Gender bias, the authors conclude, is not an inevitable consequence of development; it is a learned pattern, and what is learned early can be unlearned before it hardens. In a world where gender inequality continues to fuel conflict and injustice, the humble apples of a nursery-school experiment may mark one of the earliest and most promising points of intervention.

Subject of Research: The developmental emergence of gender schemas and gender bias in children's attribution of fair and unfair distributive actions.

Article Title: The Perception of Schemas and Gender Bias in the Attribution of Distributive Actions

Article References: La Rosa, V. L., Indiana, M. L., Borzì, E., Pirone, D., Sagone, E., Commodari, E., & Geraci, A. (2026). The Perception of Schemas and Gender Bias in the Attribution of Distributive Actions. International Journal of Early Childhood. https://doi.org/10.1007/s13158-026-00539-4

Image Credits: AI Generated

DOI: 10.1007/s13158-026-00539-4

Keywords: gender bias, gender schemas, distributive justice, child development, fairness, social cognition, gender stereotypes, developmental psychology, in-group favoritism, early childhood education, prejudice, resource distribution