Have you ever received an unexpected kindness?
A stranger in the car ahead of you paid your highway toll. Or a kind consumer picked up your tab at Starbucks.
These actions can set off a chain reaction of kindness, as you pay that kindness forward to the next unsuspecting person in line.
But when does this pay-it-forward mentality first emerge in humans?
Upstream reciprocity, or generosity, can be seen in children as young as four years of age.
At age three, 80% of children do not want to share, but at age four, 60% of children are happy to share with others.
New research at the University of Virginia found that the phenomenon is first seen in 4-year-olds.
In a pair of studies, experimenters worked with two groups. In the first study, 3- and 4-year-olds were called into a room individually and shown a transparent, locked box containing five enticing, colorful animal stickers.
The experimenter then told each child a previous toddler – let’s call her Sally – left a note sharing the location of the key to the box, which was hidden in the room.
After finding the key, opening the box and collecting their treasures, the toddlers were asked by the experimenter if they would like to share some of their stickers with a new child.
The results were clear. Most of the 3-year-olds (80%) did not want to share, while most of the 4-year-olds – about 60% of them – did.
The study’s lead author, Stefen Beeler-Duden, a graduate psychology student, calls this generosity “upstream reciprocity.”
In the second study, Beeler-Duden set out to learn what was driving the upstream reciprocity in the 4-year-olds.
To do so, he relied on a particular conceptualization of emotions, according to which the feelings are made up of an individual’s evaluation of certain parts of a situation.
Based on this model, Beeler-Duden broke down gratitude into two key parts: the gift itself and the actions of the person who provided the gift.
“Importantly, if one doesn’t recognize and approve of the person’s actions, then one should only feel a sense of joy or happiness about the gift, but not the sense of gratitude that comes from both of the key parts,” he said.
So Beeler-Duden replicated the sticker experiment with a new group of 4-year-olds and then asked them to evaluate Sally, the mysterious helper.
Was she good, bad or just OK?
He found that the children who positively evaluated Sally shared more stickers.
It was, he said, “something like the emotional experience of gratitude.”
“Moreover, children’s positive evaluations of Sally were correlated with children’s upstream reciprocity, that is, how many stickers they shared with the new child,” reads part of the new study, published in the Journal of Experimental Child Psychology.
So why are 4-year-olds more likely than 3-year-olds to share their animal stickers?
“It seems that 4-year-olds are really paying attention to these different components that are associated with gratitude, noticing not only that they received something nice, but also that this person wanted to help them,” Beeler-Duden said, “whereas it seems that 3-year-olds are not necessarily tuned fully into these different components just yet.
“It also may be that our sticker game was a little bit too difficult for 3-year-olds, because there’s a lot to keep track of.”
Still, the findings open a new window into when humans begin to pay benefits forward.
“It helps us better understand children’s upstream reciprocity,” Beeler-Duden said.
“There’s been some work looking at upstream reciprocity, but no study has really looked at when it first emerges and what motivates children to show this behavior.”
He said people have made the argument that young children engage in upstream reciprocity when they feel good. These two studies bring new evidence to the act of paying things forward.
“I think our study is designed well enough that we can say that it’s not just positive emotion driving the sharing,” he said.
“It’s something about the components of gratitude that are really playing into children’s upstream reciprocal behaviors and their pay-it-forward behavior.”
Human adults are unique in that they perform what appears to be an inordinate amount of generous behavior –; even more remarkably, empirical evidence indicates that hints of these prosocial tendencies are present even early in development.
Research shows that infants as young as eight months of age willingly share toys with family members, peers, and complete strangers –.
At 14 months of age, children will help an adult experimenter complete a goal  and will even take a cost to help others by the time they are 20 months of age .
Finally, between the ages of two and four, children begin to share resources with others voluntarily , even when those resources are easily monopolizable –.
Why do children show prosocial behavior from such an early age? To date, prosocial behavior in children has primarily been explained in terms of intrinsic motivations such as empathy, other-regarding preferences, or a desire for fair outcomes (e.g., , , –).
Under this view, children want to help others because they are motivated by that person’s need (see review: ). Other psychologists have suggested that prosocial behavior in infants and young children may also be driven by other motivations, such as wanting to prove oneself to be a useful and cooperative in-group member–i.e. wanting to present oneself favorably to others .
While a good deal of research has been done to investigate the role of intrinsic motivations on prosocial behavior in children, much less has been done to address the latter- what role, if any, do self-presentational motivations play in encouraging prosocial actions in young children?
Unfortunately, because much of the research on prosocial behavior has been conducted using methods where a beneficiary and/or parent is present and aware of the child’s actions (e.g., , ), previous work cannot determine what role, if any, concerns with self-presentation may play in guiding this behavior.
To answer this question, it may be helpful to look at the factors associated with self-presentational motivations and prosocial behavior in adults in an effort to track the developmental trajectory of these tendencies.
Recent research suggests that, at least for adults, prosocial actions stem in part from an implicit evolutionarily selfish motivation–to promote one’s reputation –. For the purposes of this paper, reputation is defined as information-based inferences about an agent’s character that may serve to inform others of the general nature of his/her possible actions in the future, thus leading to possible future reciprocation or punishment.
This is reputation in its most basic instantiation, and research suggests that even young infants respond differently to agents who have good and bad reputations –. Although they may not be aware of it, adults appear to be selective about the situations in which they choose to act prosocially.
Specifically, adults often maximize their performance of generous acts in situations in which there is an audience present to witness their actions –.
Although the presence of an audience clearly affects people’s decisions about when to act prosocially, it is not clear that adults realize the extent to which audiences influence their behavior. Indeed, research suggests that people’s prosocial tendencies are impacted by audience cues that are even incidentally presented.
Merely exposing people to eyespots or other subtle audience cues can increase prosociality in adults – (but see also –), even though people may not consciously realize their behavior is being influenced by these cues.
The tendency to act more prosocially in the presence of subtle environmental cues that could possibly be perceived as an audience suggests that our reputational motivations may draw on the simplest and most evolutionarily old of cognitive mechanisms .
Indeed, these sorts of audience-dependent changes in behavior have been observed in other less cognitively-sophisticated species ranging from cleaner wrasses (Labroides dimidiatus)  to brown capuchin monkeys (Cebus apella) .
Overall, such cues– which we will refer to here as audience cues– appear to be extremely important in determining the extent of people’s prosocial behavior across a number of situations, although it is not clear that people are consciously considering their reputations in cases in which they are affected by these cues.
In addition to being sensitive to whether an audience is present, adults’ generosity also seems to be affected by a second set of cues: those related to the amount of information other parties have regarding the presence, absence, or degree of a prosocial action .
For example, consider a case in which a man is deciding how much to give to charity in the presence of an audience that will not know any details about the amount of money given. While the presence of audience cues would likely prompt him to make a donation, his reputation would not be further enhanced by performing an exceedingly generous action because the audience members would not know the full extent of his generosity. What is needed to maximize the impact of his generosity is the presence of a second set of reputationally relevant cues–which we will refer to as transparency cues– signals that indicate that people know which kind of action has occurred. As with audience cues, there is much work suggesting that adults are more generous when the specifics of their generosity are made available to others , .
For example, Andreoni and Petrie found a strong positive relationship between the amount of information made public about donor activity and the amount of money that was actually donated .
Conversely, in situations where recipients of generosity have limited information regarding the extent of an individual’s donation, people often behave in surprisingly ungenerous ways , .
Specifically, when the recipient of a donation is unaware of the details surrounding a possible act of generosity, people tend to act in ways that best serve their personal interest rather than that of the recipient.
As in the case of audience cues, it is not clear that people are consciously thinking about reputation and intentionally changing their level of generosity in the face of transparency cues. Instead, people likely respond to transparency cues implicitly, using cognitive mechanisms developed over evolutionary time for the purpose of maximizing reputation.
Although there is reason to suspect that audience cues are conceptually distinct from transparency cues, both types of cues are often inextricably linked in real world situations. Indeed, the presence of transparency cues in non-experimental situations is often contingent on the fact that there is an audience likely to become aware of one’s actions.
However, it should be noted that the two sets of cues are in no way mutually exclusive. As noted above, people are sensitive to audience cues (eyespots) in the absence of any true agents gathering information . Additionally, even in the absence of any audience cues (when making a decision in a room by oneself) people are sensitive to whether other agents will be able to discover an ungenerous act .
Given that adults clearly modify their behavior in response to both audience and transparency cues, is it possible that young children do the same? Existing developmental literature suggests that children’s behavior more generally is influenced by the presence or opinions of others (see  for review).
For example, around age three, children begin to engage in deceptive behavior (e.g., lying) to spare the feelings of others – and to cover their own indiscretions –. By the time children reach the age of five, they are able to understand the ways in which second-hand information like gossip can influence reputation .
Interestingly, it is not until later that children explicitly understand why people would want to present themselves to others in a specific way , are able to infer audience preferences on their own –, and start to become skeptical about other people’s self-serving presentation biases –.
Indeed, it is not until eight years of age that children begin to fully understand that other people may have self-presentational motives that affect the way they behave in the presence of others . Overall, this pattern suggests that young children are sensitive to the opinions of others and modify their behavior accordingly long before they begin to grasp the concept of active reputation-management.
As a result, it is possible that children’s own prosocial behavior may also be sensitive to audience and transparency cues years before they possess explicit knowledge of the social function of, and possibility for, strategic reputation management in others.
While evidence strongly suggests that children’s behavior is generally influenced by a desire to make a good impression in the eyes of others (e.g. ), no research to date has systematically addressed the role that audience and transparency cues play in mediating children’s prosocial tendencies.
In fact, previous research looking at children’s prosocial tendencies has used a wide variety of methodologies with differing degrees of audience and transparency cues, making it difficult to compare across studies.
For example, prosocial testing paradigms in children range from those in which children’s actions are anonymous even to experimenters , to situations in which both the subject and the recipient of the prosocial act are present and fully aware of one another’s actions –.
Furthermore, even when audience and transparency cues are experimentally manipulated, they are often confounded with other factors such as the in-group/out-group status of the recipient , –, making the effects of these cues virtually indistinguishable from other factors.
Overall, most authors fail to discuss or account for audience or transparency effects when interpreting levels of prosociality (but see: , ); as a result, there is still much to learn regarding whether young children’s prosocial decisions are sensitive to these cues.
The current study aimed to address this gap in the literature by directly testing the extent to which children’s prosocial behavior is affected by audience and transparency cues using a no cost allocation task. We did this by independently manipulating the visibility of the recipient (varying whether the recipient was occluded by a large opaque screen) and the transparency of the allocations to the recipient (presenting the allocations in either opaque containers or transparent containers).
We chose to test five-year-olds because previous research has shown that children at this age can successfully represent the goals and beliefs of others (for review see ) and thus we knew that children of this age could understand what the recipient knew about different kinds of actions.
Our question, then, was whether five year-olds’ decisions about whether to be generous would be sensitive to the amount of information available to the recipient. We tested pairs of children who were classmates and, thus, likely to interact with one another in the future.
Given the notion that reputational motivations are strongly influenced by the likelihood for future reciprocation or punishment, pairing children with possible future collaborators was the truest way to test for such reputational concerns.
Overall, the logic behind the current study is as follows: if, in fact, prosocial behavior in children is largely intrinsically motivated, our subjects should act generously, regardless of if the recipient is aware of their actions. However, if children’s prosocial behavior is sensitive to extrinsic social factors, we should see variation in their allocation decisions relative to the different conditions.
Specifically, if children are sensitive to audience cues, then five year-olds should act more generously on the allocation task when the recipient is visible than when the recipient is not. Additionally, if children are sensitive to the transparency of their actions when making prosocial decisions, then they should behave more generously when allocations are presented in transparent containers than when they are presented in opaque containers.
Furthermore, if children’s prosocial decisions in this task are driven largely by extrinsic social factors, then our participants should act neutrally or even ungenerously when the recipient does not have knowledge about their actions.
Overall, by manipulating both the visibility of the recipient as well as the information available to the recipient, we were able to gain insight into the ways in which audience and transparency cues influence children’s prosociality as well as the extent to which children’s prosociality is impacted by extrinsic factors.
University of Virginia