The Role of the Observer in Goal-Directed Behavior

Abstract

Systems producing goal-oriented behavior manage to approach the desired goal from multiple initial states, circumventing the obstacles they meet along the way. The mathematical description of this type of evolution is formulated in terms of an open subsystem whose entropy decreases in time. Yet ultimately, the laws of physics are reversible, so entropy variations are necessarily a consequence of the level of description the observer has chosen to employ. In order to reconcile different levels of descriptions, systems yielding goal-directed behavior must transfer the information about initial conditions and about circumvented obstacles to other degrees of freedom outside their own boundaries. To operate steadily, they must consume ordered degrees of freedom provided as input, and be dispensed of disordered outputs that act as wastes from the point of view of the aimed objective. In short, goal-oriented behavior requires metabolism, even if conducted by non-living agents. Here I argue that for a physical system to display goal-directed behavior, its borders must be carefully tailored so as to entail the appropriate information balance sheet. In this game, observers play the role of tailors: They design agents by setting the limits of the system of interest. Goal-directed behavior hence only exists in the eye of the beholder. Brain-guided subjects perform this creative observation task naturally, implying that the observation of goal-oriented behavior is a goal-oriented behavior on its own. Minds evolved to cut out pieces of reality and endow them with intentionality, because ascribing intentionality is an efficient way of modeling the world, and making predictions. One most remarkable agent of whom we have first-hand evidence of its goal-pursuing attitude is our own self. Notably, this agent is simultaneously the subject and the object of observation.