Summary
Despite cultural and individual variation, humans are a judgmental bunch [1]. There is accumulating evidence for early social and moral evaluation as shown by research with infants and children documenting the notion that some behaviors are perceived as right and others are wrong [2]. Moreover, social interactions are governed by a concern for fairness and the others’ well-being [3, 4]. However, while generosity increases between infancy and late childhood, it is less clear what mechanisms guide this change [5]. Early predispositions towards prosociality are thought to arise in concert with the social and cultural environment, developing into adult morality, a complex incorporation of emotional, motivational, and cognitive processes [6, 7]. Using EEG combined with eye-tracking and behavioral sharing, we investigated, for the first time, the temporal neuro-dynamics of implicit moral evaluation in 3–5 year old children. Results show distinct early automatic attentional (EPN) and later cognitively controlled (N2, LPP) patterns of neural response while viewing characters engaging in helping and harming behaviors. Importantly, later (LPP), but not early (EPN) waveforms, predicted actual generosity. These results shed light on theories of moral development by documenting the respective contribution of automatic and cognitive neural processes underpinning social evaluation, and directly link these neural computations to prosocial behavior in children.