Edward L. Thorndike, answered from the texts and cited to the page.
Connectionism is the doctrine that the mind is, at bottom, a system of bonds — connections between situations and responses — formed, strengthened, and weakened according to three laws: readiness, exercise, and effect. The law of effect is the central one. Of the many responses an animal or a person makes in a given situation, those accompanied by satisfying states of affairs grow stronger; those accompanied by annoyance weaken and disappear.1
Exercise strengthens bonds through use; disuse weakens them. That is the whole machinery. There is no need to invoke faculties of memory, attention, or reasoning as mystical powers weighting the dice — that opinion, I am satisfied, is simply false and would be useless to human welfare even if it were true.2 What the chick in the pen shows you is the mechanism in its plainest form.
Put the animal in a situation, and it responds; the response that brings satisfaction is gradually selected, trial by trial, until the bond is fixed.3 The learning of the chick, the turtle, the kitten — characterized, I insist, by the absence of inferential thinking, by the absence of effective use of ideas of any sort — is adequately accounted for as the strengthening and weakening of bonds between a situation present to sense and responses in the nervous system which issue then and there in movement.4
The human learner differs in the number and fineness of the bonds he can form, and in the fact that ideas do sometimes intervene between situation and response; but the bonds themselves are built by the same laws. Imitation and ideo-motor action — the two great rival accounts of how connections form — I find without adequate evidential support.5
The behavior of other men does shape learning, but only as a provider of situations to which habit has already bound responses, or as a model that affects the satisfyingness of one's own acts; the binding force is always the laws of exercise and effect, not some general imitative tendency operating directly.6 Give me the situation, the response, and the consequence that follows, and I will give you the connection — and the connection is the mind.
Of the bonds which the animal's behavior makes between a situation and responses those grow stronger which are accompanied by satisfying states of affairs, while those accompanied by annoyance weaken and disappear.Educational Psychology Vol 2 The Psychology of Learning
This opinion is vanishing from the world of expert thought and no more need be said about it than that it is false and would be useless to human welfare if true.Educational Psychology Vol 1 The Original Nature of Man
After a number of trials the chick will, when put in pen No. 2, go at once to pen No. 1, and thence out.Educational Psychology Vol 2 The Psychology of Learning
The three cases of learning quoted are adequately accounted for as the strengthening and weakening of bonds between a situation present to sense and responses in the nervous system which issue then and there in movement.Educational Psychology Vol 2 The Psychology of Learning
Of this I can find no evidence.Educational Psychology Vol 1 The Original Nature of Man
The behavior of others is a very important provider of situations to which habit has bound responses like the behavior seen. But the binding force is habit — that is, the laws of exercise and effect — not imitation in the sense required by the theory in question.Educational Psychology Briefer Course