Altruistic helping — the act of giving away something desirable, even at a cost to oneself – is perhaps no more evident than when it comes to food.
Human adults often respond to hungry people, whether through food banks or fundraisers, or by simply handing over their lunch.
But when, and how, does that spirit of giving start?
New research by the University of Washington’s Institute for Learning & Brain Sciences, or I-LABS, finds that altruism may begin in infancy. In a study of nearly 100 19-month-olds, researchers found that children, even when hungry, gave a tasty snack to a stranger in need.
The findings not only show that infants engage in altruistic behavior, but also suggest that early social experiences can shape altruism.
The study is published online Feb. 4 in Scientific Reports.
“We think altruism is important to study because it is one of the most distinctive aspects of being human.
It is an important part of the moral fabric of society,” said Rodolfo Cortes Barragan, a postdoctoral researcher at I-LABS and lead author on the study.
“We adults help each other when we see another in need and we do this even if there is a cost to the self. So we tested the roots of this in infants.”
Nonhuman primates have been found to cooperate, and to share resources under restricted conditions.
But nonhuman primates, such as chimpanzees, don’t actively hand over delicious food that they need themselves.
I-LABS researchers wanted to test whether human infants were able to act beyond self-interest, when faced with one of the most fundamental biological needs: food.
For this study, researchers chose kid-friendly fruits — including bananas, blueberries and grapes — and set up an interaction between child and researcher.
The goal: to determine whether the child would, without encouragement, verbal instruction or reinforcement, spontaneously give an appealing food to an unfamiliar person.
In the experiment, the child and the adult researcher faced each other across a table at I-LABS, and the researcher showed the child a piece of fruit.
What happened next was determined by whether the child was in the control group, or the test group.
In the control group, the researcher gently tossed the piece of fruit onto a tray on the floor beyond reach but within the child’s reach.
The researcher showed no expression and made no attempt to retrieve the fruit.
In the test group, the researcher pretended to accidentally drop the fruit onto the tray, then reach for it unsuccessfully.
That reaching effort — the adult’s apparent desire for the food — seemed to trigger a helping response in the children, researchers said: More than half the children in the test group picked up the fruit and gave it to the adult, compared to 4% of children in the control group.
In a second experiment with a different sample of children, parents were asked to bring their child just before their scheduled snack or mealtime — when the child was likely to be hungry.
Researchers reasoned that this would raise the “cost to self” that defines altruism.
The control and test group scenarios were repeated, but with children who were now more motivated to take the fruit for themselves.
The results mirrored those from the previous study. Fully 37% of the test group offered the fruit to the researcher while none of the children in the control group did so.
“The infants in this second study looked longingly at the fruit, and then they gave it away!” said Andrew Meltzoff, who is co-director of I-LABS and holds the Job and Gertrud Tamaki Endowed Chair in psychology. “We think this captures a kind of baby-sized version of altruistic helping.”
The research team also analyzed the data in different ways — whether children offered fruit on the first trial of the experiment or got better during the process, for example, and whether children from particular types of family environments helped more.
The researchers found that infants helped just as well on the very first trial of the experiment as on later trials, which Barragan said is informative because it shows that the children did not have to learn to help during the study and needed no training.
Indeed, children spontaneously and repeatedly helped a person from outside of their immediate family.
A new study by the University of Washington’s Institute for Learning & Brain Sciences finds that very young children are willing to offer food and help others.
The researchers also found that children with siblings and from certain cultural backgrounds were especially likely to help the adult, indicating that the expression of infant altruism is malleable.
These results fit well with previous studies with adults that show positive influences of having a cultural background that emphasizes “interdependence,” that is, a background that places particular value on how much an individual feels connected to others.
Said Barragan, “We think certain family and social experiences make a difference, and continued research would be desirable to more fully understand what maximizes the expression of altruism in young children.
If we can discover how to promote altruism our kids, this could move us toward a more caring society.”
Rechele Brooks, an I-LABS research scientist, was a co-author.
Funding: The study was funded by the Templeton World Charity Foundation, a National Science Foundation Broadening Participation Postdoctoral Research Award to Barragan, and the I-LABS Ready Mind Project.
The ubiquity of cooperating, helping and sharing distinguishes human societies from those of other primates, and is arguably what makes human societies so successful in the animal world [1–4].
In recent years, understanding the origins and development of prosocial behavior has attracted widespread interest from a variety of fields including psychology [1–3], anthropology , economics [6,7], education  and public policy [9,10].
Elucidating the bases of prosocial behavior not only helps us better conceptualize ourselves as humans from an evolutionary perspective, but also provides important insights for understanding communication, interaction, collaboration and other aspects of social cognition [1,3,11].
Moreover, an emerging body of research on enhancing prosociality provides guidance for promoting cooperation in real-life circumstances and organizations, which is essential for addressing some of the most pressing issues in the modern society, including climate change, large scale conflicts, and inequality [3,4,12].
Prosocial behavior can be effectively enhanced by interpersonal synchrony [13–17]. In both adults and children, synchronous social activities such as singing, dancing and joint music making increase social bonding and facilitate subsequent cooperation and helping [15,18–23].
Infants as young as 14 months are more likely to engage in prosocial behaviors after being bounced in synchrony with the experimenter [24–26].
Similar effects are found with synchronous movement in non-musical contexts. In both adults and children, walking, tapping fingers, clapping hands and rocking chairs in synchrony have all been found to have affiliative effects, thereby enhancing prosociality [13,16,17,27].
Infants studies also show that synchronous movements in non-musical contexts increase helpfulness, although helping is more delayed than in musical contexts .
The positive social effects of interpersonal synchrony have also been found in naturalistic settings.
Spontaneous synchrony in body movements during natural interactions is correlated with higher positive emotions, and it is likely that synchrony is playing a causal role .
A prevalent line of research uses the term synchrony to describe how individuals make the same movements at the same moment in time [13,17].
In these studies, interpersonal synchrony is typically manipulated by having groups of two or more people performing the same actions at the same time, such as tapping fingers to a beat , and results show that such synchronous rhythmic movements produce higher bonding effects than similar movements occurring at different tempos.
These findings appear to suggest that “similar is better” for producing prosocial effects, as participants’ behaviors in the synchronous condition are always more similar, spatially and temporally, compared to the asynchronous condition.
This argument is supported by an extensive body of research on prosocial effects of mimicry known as the “chameleon” effect [30–32].
Recent perspectives of interpersonal dynamics are challenging this predominant approach, arguing that the structure of interaction should be examined in broader contexts.
For example, the interpersonal synergies perspective holds that interpersonal coordination should be viewed as a dynamic soft-ensemble system which minimizes variability in task-relevant movements but allows degrees of freedom to range freely in task-irrelevant areas .
Research guided by this framework has shown that increasing similarity is not necessarily beneficial to interpersonal interaction [34–36].
Instead, a mixture of similar and complementary behaviors is more beneficial for promoting collective interests and effective coordination [34,35].
This view also finds support in music studies. For instance, research on music improvisation found that performing freely to an open-ended backing track increased coordination and a sense of unity more so than playing under a predesigned structure .
Clearly, then, in order to further understand how synchrony occurs and influences social bonding, we need to expand the current standard paradigm of having participants perform highly similar, time-locked behaviors and begin to explore interactions with more variability and dynamics.
The interaction mode described in the interpersonal synergies perspective is common in real-life synchronous interactions.
People frequently engage in activities where their actions are coordinated in time but their movements are different . Examples include partner-dancing, percussion ensemble, and two people moving a piece of heavy furniture.
Recent studies have shown that simultaneous, complementary behaviors during interaction can produce positive social effects comparable to those of synchronous and identical behaviors.
With 14-month infants, Cirelli et al. found that synchronous but anti-phase bouncing has prosocial effects that are comparable to in-phase bouncing .
Freestyle adult dancers who make synchronous but non-identical movements subsequently recall more information about each other than those dancing asynchronously .
Catmur and Heyes had participants perform hand or foot lifting actions while observing hand and foot lifting actions on a computer screen . Increased feelings of closeness and helpfulness were comparable for contingent-but-different responses (e.g. hand lifting produced foot lifting, and foot lifting produced hand lifting) and contingent-and-similar responses (e.g. hand lifting produced hand lifting), compared to non-contingent responses.
Taken together, these studies suggest that synchrony with some freedom in movements can have powerful bonding effects.
To the best of our knowledge, few studies have directly examined the element that is the most important to synchrony, namely timing.
In contrast to mimicry and movement matching, synchrony stresses the timing, rather than the contents of the interactors’ behaviors . The time interval between movements may play an important role in coordinating synchronous movements and is thus a plausible source of prosocial effects.
Specifically, temporal predictability, that is the predictive relationship between the onset time of one participant’s movement and that of the other participant’s movement, might contribute to the prosocial effect of synchronous activities.
Although there is no direct evidence for this claim, past research provides some insights in support of our hypothesis.
Specifically, temporal predictability guides behaviors in time-locked interpersonal coordinative activities, musical and non-musical , and therefore makes salient collective goals and shared intentionality which could increase prosociality .
Consider walking together. Without the aid of outside cues, coordinating one’s steps to walk side by side in perfect unison usually requires predicting when the other person will take a step. Another example is a jazz jam session in which each musician is playing different melodies on different beats.
While the exact content and movement of each musician are hard to predict, everyone follows the same beat pattern. Temporal predictability, in this case dictated by a consistent beat, is the “common ground” that the musicians share, and it is crucial to maintaining a cohesive, interconnected ensemble.
Based on the infant and adult literature on the social effects of synchrony, together with the theory of shared intentionality and prosocial behavior, we hypothesized that temporal predictability plays an important role in producing prosocial effects in interpersonal coordinative activities.
This question has previously been explored with infants experiencing passive movements . In this study, Cirelli et al. found that being bounced in synchrony with the experimenter can increase prosociality in infants regardless of whether the movements were evenly spaced or following random beats.
The infants were held by an adult bouncing to the beat instead of generating movements themselves. It is possible that older children engaging in active coordination will be more affected by the shared experience.
It indeed would be particularly important to study the effects of interpersonal effects in kindergarten children. Nearly all children in China, and in many other countries, attend kindergarten, and one goal of kindergarten is to socialize children.
Therefore, this is an ideal age group and environment where simple tasks that are empirically shown to increase prosocial behavior might eventually be incorporated into curricula. We conducted pilot study using kindergarten children, and found that five-year-old children are capable of learning to play instruments in response to visual guidance.
We thus chose to study this age group and hypothesized that temporal predictability in active coordination would generate prosocial behavior as early as five years.
We designed a percussion game that guides children’s behaviors with visual stimuli presented on a computer screen and manipulated temporal predictability by adjusting beat predictability (evenly spaced beats vs. unevenly spaced beats).
Five-year-old children, in same-sex dyads, played a duet: One child played the drum while the other played the bell, and they played in alternation as opposed to playing at the same time.
By introducing this turn-taking dynamic where the participants’ movements are separated by a time interval, we were able to manipulate beat predictability without confounding it with simultaneous behavioral matching.
We then measured children’s cooperative problem-solving behavior and spontaneous helping behavior in two subsequent tasks: an apron-buttoning task, which assessed cooperative problem solving; and a beads task adapted from Kirschner and Tomasello , which examined whether a child would help a partner who had an accident.
We also manipulated rhythmic similarity and predictability by having the pair play rhythmic patterns that were similar, predictable, or independent from each other. The prosocial effect of movement similarity is well-documented in the literature on both adults and children [30–32,42].
Recent adult studies have found that predictable but different movements can produce prosocial effects comparable to those of similar movements . We thus predicted that rhythmic similarity and predictability in terms of relative movement patterns would produce prosocial effects when a temporal interval is added between the movements of the dyad.
University of Washington