Sharing is Caring

In a recent study, Fehr et al described the sharing attitudes of children ages 7-8. This experiment made use of a paradigm similar to the one used by neuroeconomics to study decision making and fairness in adults. The experimenters presented the children with candy and a picture of another child. The child was told to divide the candy between themselves and the pictured child.  Largely all of the children chose to distribute the sweets equally. In comparison, children 3-4 are very much self-centered when it comes to food and will not share food at all. However, children at this age do show some signs of altruism, such as instrumental helping. In others words opening a door or helping to carry a heavy object.

Also, of noted interest, the authors mention that chimpanzees display no "other regarding preferences". Thus, it seems a closest evolutionary cousins have not developed an extensive notion of sharing.

In neuroeconomics, a typical paradigm involving the allocation of resources is used to study decision making.  The experiment goes you and another individual are to split a sum of money. One individual is told to decide which percentage of x$ you get and he gets. You then get to accept the offer or decide that neither of you receives anything. The results of this study were  if people felt they were being cheated they would forgo any sort of payment to spite the other particpant. Logically this is not in their best interest. Regardless of what is offered you might as well accept and be better off than you were before. This studies were done in fMRI and scans showed that "unfair" offers elicited heightened activity in the anterior insula, as well as the dorsolateral prefrontal cortex.Activity of the insula, known for its involvement in emotion suggests that decisions, are not purely cognitive in origin. This experiments illustrates the notion that people are not rational maximizers, and sometimes "reason doesn't matter".

Link to Nature article

Link to neuroeconomics paper