Toddlers have an instinct for fairness and generosity

Anecdotally, anyone who's spent time around toddlers knows that they mostly don't like sharing their toys. Together with research showing that toddlers, like adults, get pretty attached to their things and are reluctant to give them up, this has led to a popular belief that toddlers are selfish by nature.

But a team of developmental psychologists led by Julia Ulber has published new evidence in the Journal of Experimental Child Psychology that paints a more heart-warming picture. These psychologists point out that most past research has focused on how much toddlers share things that are already theirs. The new study looks instead at how much they share new things that previously no one owned. In such scenarios, toddlers frequently show admirable generosity and fairness.

There were two main experiments. The first involved 48 pairs of 18-month-old or 24-month-old toddlers sitting together at table, in the middle of which was a small container containing four marbles. If the toddlers took a marble and placed it in a nearby jingle box, it made a fun noise. The point of the set-up (repeated four times for each toddler pairing) was to see how the pairs of toddlers would divvy up the marbles between them.

Most of the time (44 per cent) the toddlers divided the marbles up fairly, 37 per cent of the time unequally (i.e. one child took 3 marbles), and 19 per cent of the time one child took all the marbles. This all took place pretty calmly, with marble steals happening only rarely. Overall, the experiment "rarely left one peer empty-handed," the researchers said, "and thus [the results] do not match the picture of the selfish toddler."

In a follow-up experiment with 128 pairs of two-year-olds, the set-up was more complex and this time, unlike the first experiment, none of the toddlers knew each other. Again, the children sat at opposite sides of a table with marbles on offer, but this time they had to pull a board sticking out of their side of the table to get the marbles to roll down into a reachable tray (marbles could again be used to make a jingle box play music). When the apparatus was designed so that there was one shared tray between the two toddlers, the toddlers shared the marbles equally about half the time. And this rose to 60 per cent if they'd had to collaborate by pulling the boards together to release the marbles.

In another variation of the set-up – possibly the most illuminating – the children had separate trays, and sometimes the researchers made it so that one child received three marbles in their tray and the other child just one. On about one third of these occasions, the results were delightful – the "lucky child" with three marbles gave up one of their marbles to their partner, willingly and unprompted. "This is the youngest age ever observed at which young children make sacrifices in order to equalise resources," the researchers said.

These acts of fairness were greater when the marbles were colour-coded so that two marbles matched the colour of one child's jingle box (located behind them) and the other two matched the other child's.  This colour-coding effect on generosity might be due to the children interpreting the colours as a sign of ownership (i.e. the idea being that this or that marble belongs to the other child because it matches their jingle box), or the colours might simply have helped the children, with their limited numerical skills, to identify a fair split in the numbers of marbles.

The researchers said their results showed that "young children are not selfish, but instead rather generous" when they're sharing resources among themselves, and that more research is needed to establish "in more detail the prosocial or other motives that influence the way in which young children divide resources."

Further reading

Ulber, J., Hamann, K., & Tomasello, M. (2015). How 18- and 24-month-old peers divide resources among themselves Journal of Experimental Child Psychology, 140, 228-244 DOI: 10.1016/j.jecp.2015.07.009