What Suboptimal Choice Tells Us About the Control of Behavior

When animals make decisions that are suboptimal, it helps us to identify the processes that have evolved to produce this behavior. In an earlier article, I discussed three examples of suboptimal choice or bias (Zentall, 2016): (a) sunk cost, the tendency to continue on a losing project because of the amount already invested; (b) unskilled gambling, in which the loss is greater than the return; and (c) justification of effort, the bias to prefer conditioned stimuli that in training required more effort to obtain. Here I discuss three additional examples of suboptimal choice that we have studied in animals: (a) when less is better, in which animals prefer one piece of food (one preferred item) over two pieces of food (one preferred item plus one less preferred item); (b) suboptimal choice on the ephemeral choice task, in which animals prefer one piece of food now over two pieces of the same food, one now but the second briefly delayed; and (c) suboptimal choice in the midsession reversal task, errors of anticipation and perseveration. Each of these examples may help to identify the relative limits on behavioral flexibility found when animals are exposed to conditions that may be different from those that they would normally encounter in their natural environment. They also may help us to understand the origins of similar behavior when it occurs in humans.