A study coordinated by a team of Italian and international universities — the University of Milano-Bicocca, the London School of Economics, the University of Stavanger and Northwestern University — and published in the prestigious journal Nature Human Behaviour under the title “Stable intuition and the rise of deliberative prosociality in childhood” investigated a central question in behavioural science: how prosocial behaviour develops in children and, in particular, whether this behaviour emerges as an intuitive response or is built through reflection and choice as children grow.
To answer these questions, the researchers involved 537 Italian children aged between 3 and 10. Each child was randomly assigned to one of two conditions: a time-pressure condition, designed to encourage intuitive responses, or a time-delay condition, designed to encourage deliberate responses. They then took part in a series of five games in which sweets were at stake. In the first condition, they had to respond within 10 seconds; in the second, they had to wait at least 10 seconds before deciding. By distinguishing between rapid and considered decisions at every age, the researchers were able to observe how two different forms of kindness developed according to different timelines.
The children completed several classic behavioural economics tasks, including the Public Good Game, the Dictator Game, the Ultimatum Game and the Deception Game, which reflect different social behaviours, ranging from cooperation to altruism and honesty. They had to decide how many sweets to place in a shared container; how many to offer to a stranger who would never be able to reciprocate; whether to reject an unfair allocation, even at the cost of leaving both parties empty-handed; whether to lie about the colour assigned to them when lying offered a greater advantage; and, finally, in two scenarios inspired by the “trolley problem”, whether to harm one child in order to save five. In total, they made 19 decisions. The partners were fictional, although the children believed they were real.
«The main finding was that, among younger children,» explains Elena Nava, one of the two coordinators of the study and a researcher in Developmental and Educational Psychology at the University of Milano-Bicocca, «prosociality appears to be stronger when they decide quickly and therefore intuitively. With age, however, deliberative prosociality increases: older children are not prosocial only “instinctively”, but seem increasingly to integrate cooperation, altruism and honesty into reflective processes.»
The message, therefore, is not that children are simply “good by nature” or that they learn to be so only as a result of a developmental process. «Growing up does not necessarily mean abandoning social intuition; rather, it means learning to transform it into a more conscious choice,» the researcher adds. At the age of three, children are significantly more prosocial when they act instinctively than when they are required to deliberate. This “intuitive advantage” suggests that, at the beginning of the preschool years, children’s instinctive response is already oriented towards the common good.
The study’s main impact is that it «changes the way we think about the development of prosociality in childhood. It does not simply show that young children can be cooperative, altruistic or honest,» Nava continues, «but also that these behaviours can be organised within a common dimension and that the way in which this dimension is supported changes: initially more by intuition and subsequently increasingly by deliberation.»
Across the entire age range from 3 to 10, the level of intuitive prosociality changes very little. What changes is deliberative prosociality. Children do not necessarily become more “instinctively” kind as they grow; rather, their ability to reason their way towards kindness becomes aligned with their natural impulses.
The study may also influence approaches to education and social interventions. It suggests that prosociality does not need to be “built from scratch”: young children already possess intuitive responses oriented towards positive social behaviours. Education could therefore go beyond teaching abstract moral rules and help children transform early prosocial inclinations into conscious, stable choices that can be applied across different contexts. In other words, it could help them independently achieve the same kindness or sociability even when they have time to reflect.