“No. however, nothing can be found there. ” That is a bad attitude for an animal when it has to decide whether moving to a new grazing site is profitable or too dangerous.

Reasonably optimistic individuals get the best of their stomachs, live the healthiest, and often avoid predators.

This according to U.S. and Israeli researchers who simulate searching for food using a computer model.

In it, animals moved in changing environments and learned from their experiences.

The world was partly unpredictable, as in real life. Quite optimistic people fared better than top optimists, realists, or pessimists.

Sometimes, however, there was an advantage to pessimism as well. Most clearly, it improved survival if a fairly homogeneous environment suddenly deteriorated. That’s when the previous realism turned into over-optimism.

People tend to lean towards optimism, except in depression. A similar trend has been observed in other species, the researchers point out Frontiers in Ecology and Evolution.