Why did evolution not give us a utility function that is offspring alone? Why do we care intrinsically about other outcomes, such as food, and what determines the intensity of such preferences? A common view is that such other outcomes enhance fitness and the intensity of our preference for a given outcome is proportional to its contribution to fitness. We argue that this view is incomplete. Specifically, we show that in the presence of informational asymmetries, the evolutionarily most desirable preference for a given outcome is determined not only by the significance of the outcome, but by the Agent’s degree of ignorance regarding its significance. Our model also sheds light on the phenomena of peer effects and prepared learning, whereby some peer attitudes are more influential than others.

Joint work with Luis Rayo (London School of Economics, United Kingdom)