The developmental foundations of human fairness

Abstract

New behavioural and neuroscientific evidence on the development of fairness behaviours demonstrates that the signatures of human fairness can be traced into childhood. Children make sacrifices for fairness (1) when they have less than others, (2) when others have been unfair and (3) when they have more than others. The latter two responses mark a critical departure from what is observed in other species because they enable fairness to be upheld even when doing so goes against self-interest. This new work can be fruitfully combined with insights from cognitive neuroscience to understand the mechanisms of developmental change. Fairness is a hallmark of our species's ability to maintain cooperative relationships with large numbers of unrelated — and often unfamiliar — others. However, there is much debate over the psychological foundations of this sense of fairness. Which aspects of fairness are engrained in our biology and which depend on learned social norms? What are the psychological mechanisms and motivations that give rise to human fairness? Why does fairness appear to drive decisions in some contexts but not others? To answer these questions, it is critical to understand how fairness emerges in child development, as studies of adults alone do not allow us to differentiate between psychological processes that are acquired through socialization and those that have deeper biological roots. Indeed, a complete understanding of any behaviour requires a description of its developmental course and an examination of what causes behavioural change over the lifespan1,​2,​3. Studies of child development can provide unique insight into the psychology of fairness in important ways: first, developmental data can help to identify the aspects of fairness that are foundational and those that are more malleable. Second, charting how fairness behaviour changes across development can shed light on the specific cognitive mechanisms that enable its emergence and expression. Finally, combining insights from development with work examining how fairness is instantiated at the neural level can help us to understand the psychological foundations on which the human sense of fairness is built. In this Review, we appraise and integrate recent developmental and neuroscientific evidence on fairness. The resulting neurodevelopmental perspective provides novel insights into the foundations of fairness in our species. First, we argue that the signatures of our uniquely human sense of fairness are present in childhood. We then summarize the current state of knowledge for neural mechanisms that support fairness and highlight recent work on the developmental neuroscience of fairness. Last, we identify key neural processes that change during childhood and propose how the developmental integration of these systems can explain the temporal emergence of the human sense of fairness

The development of children's preferences for equality and equity across 13 individualistic and collectivist cultures

“…Consistent with this perspective, people react negatively to violations of unfairness and consider evidence of past fairness to be a sign of a good social partner (Shaw, DeScioli, & Olson, ). Even children are motivated to behave fairly; however, conceptions of fairness change with age in childhood (McAuliffe, Blake, Steinbeis, & Warneken, ).…”

Longitudinal relations of preschoolers’ dispositional and situational anger to their prosocial behavior: The moderating role of shyness

“…Further, the current study provided evidence that children as young as 3.5 years understand fairness and react negatively to unfairness (LoBue et al, ; Olson & Spelke, ). This is important because before children are capable of engaging in fairness‐related behaviors (e.g., punishment of unfairness or subsequent prosocial behavior), they first develop an aversion unfairness when they learn that social interactions are governed by the norm of fairness (McAuliffe et al, ). This aversion, commonly reflected by spite, anger, or upset, is often demonstrated by 4‐ and 5‐year‐olds (Helwig & Turiel, ; Konstantareas & Desbois, ).…”

“…However, we suggest that even when the unfair treatment is directed toward oneself, at least at young ages, such anger often might reflect moral sensitivity. Moreover, researchers suggest that children acquire an understanding of third‐person unfairness in middle childhood (Bereby‐Meyer & Fiks, ; see McAuliffe et al, for a review); thus, it is possible that responses to unfairness toward oneself may be an important precursor to empathic outrage. Nevertheless, in future work, it is worthwhile to differentiate between anger at one’s own mistreatment versus anger based on witnessing unfairness toward another (i.e., empathic anger).…”

“…Specifically, we included children’s dispositional anger which reflects general irritability/frustration, and a specific type of situational anger elicited by unfairness toward the target child (which is considered an important aspect of morality; Haidt & Graham, ). Although our situational measure did not assess children’s anger in response to a third person being treated unfairly, research suggests that children’s anger reaction in response to unfairness directed at the self is a developmental precursor of anger reactions in response to unfairness directed at others (i.e., moral outrage, or empathic anger; McAuliffe, Blake, Steinbeis, & Warneken, ). Further, we sought to examine the interaction of two emotionally driven constructs (i.e., anger and shyness) to children’s prosocial behavior because shyness might neutralize the behavioral tendencies elicited by anger.…”

The Normative Turn in Early Moral Development

“…McAuliffe, Blake, Steinbeis, and Warneken [2017] reviewed studies using another task to investigate young children's sense of fairness in distributing resources. The basic task [as used by, e.g., McAuliffe, 2011, andMcAuliffe, Jordan, &Warneken, 2015] is that an adult sets up a potential distribution between the child and some other child on an apparatus.…”