Cumulative Record. Chapter 12: The Science of Learning and the Art of Teaching. Quote 13

In spite of great phylogenetic differences, all these organisms [pigeons, rats, dogs, monkeys, humans] show amazingly similar properties of the learning process. It should be emphasized that this has been achieved by analyzing the effects of reinforcement and by designing techniques which manipulate reinforcement with considerable precision. Only in this way can the behavior of the individual organism be brought under such precise control. (pp. 182-183)