Thoughts provoked by walking through Washington Square Park to NYU yesterday by one route and then walking back by another route:
Faced with a decision as a walker about turning toward my destination or going straight toward it, I tend to turn. That tendency is sufficiently strong that it often results in my taking different routes when I walk from A to B than when I walk back from B to A, even if I walk between the two points a fair amount and even if one route is better.
When I drive, there's a somewhat different anomaly in my route choices: I tend to be overly reluctant to double back. One result of that tendency is that I took quite different routes to and from work for two years in a job I had in the 1980s in which my commute started on a one-way street that forced me to go in one direction before turning.
I think that these tendencies for me as an individual to deviate from optimality can be explained with a combined evolutionary psychology and value competition story. The variation in routes that results from a "turn" tendency and an opposing "stay straight" tendency, even if excessive from the point of view of the individual's welfare, has beneficial properties for social organisms like people, or for that matter chimpanzees or fish. Calling "turn" a value competing with "stay straight" (or calling "don't double back" a value competing with "double back") may seem like a stretch. But I don't believe it is; the function of "turn" and "stay straight" in relation to individual and collective decision is quite parallel to that of "id/pleasure" and "superego/duty" and other dichotomies in relation to individual and collective decision.
Out of these reflections, a VC prediction: Behavioral experiments in humans and other social animals will show a substantial number of individual subjects who deviate from optimal routes because of a "turn" proclivity or value and a very comparable number of other individual subjects who deviate from optimality because of a "stay straight" proclivity or value. (In asocial animals, on the other hand, individual deviations from rationality should be less, given the lack of benefit such deviations confer on the group.) The gist of the prediction: equality in the numbers of those with a suboptimal tilt toward "turn" and a suboptimal tilt toward "straight."