Up until about the age of seven, children across the world show similar levels of sharing behaviour as revealed by their choices in a simple economic game. The finding comes courtesy of Bailey House and his colleagues who tested 326 children aged three to fourteen from six different cultural groups: urban Americans from Los Angeles; horticultural Shuar from Ecuador; horticultural and marine foraging Fijians from Yasawa Island; hunter-gathering Akas from the Central African Republic; pastoral, horticultural Himbas from Namibia; and hunter-gatherer Martus from Australia.

In one game, the children had to choose whether to take two food rewards for themselves or take one and give the other to their partner. When this partner was sat before them, a similar pattern was found across the diverse cultural groups - progressively from age three to about seven or eight the children grew more selfish. That is, the older the child, up to seven or eight, the more likely they were to keep both treats for themselves.

Intriguingly, aged eight to fourteen, the behaviour of the children varied depending on the culture they belonged to.