Selection by reinforcement: A critical reappraisal

Abstract

This essay is a critical reappraisal of the idea of ontogenetic selection by reinforcement, according to which learning, specifically conditioning, in the individual animal is deeply analogous to phylogenetic evolution by natural selection. I focus on two general versions of this idea. The traditional Skinnerian version restricts the idea to operant conditioning and excludes Pavlovian conditioning, based on a sharp dichotomy between the two types of conditioning. The other version extends the idea to Pavlovian conditioning, based on a unified principle of reinforcement that applies to both types of conditioning, and linked to a neural-network model. I criticize both versions on the same grounds, for being: 1) unable to capture Pavlovian conditioning; 2) unnecessary to formulate said model and use it for explanation and prediction (its combination with a genetic algorithm allows for a substantive contact with the theory of evolution by selection, without the idea of selection by reinforcement), and 3) metaphysically unsound. Non-selectionist accounts of conditioning are not only possible but also more intelligible, explanatory, and heuristic.

Keywords: Genetic algorithms; Metaphysics; Neural networks; Pavlovian conditioning; Selection by reinforcement.