ABSTRACT
One of the goals of a scientific psychology is to describe general laws. This textbook, which includes the word principles in its title, attempts to specify some general, maybe even universal, principles of learning and memory. However, you and I realize that these generalities do not hold for each and every occasion. There are exceptions to the principles. Individual differences are one source of variations to the general principles of learning. Each person is unique. The combination of genes, physical constitution, environment, and life experiences causes each of us to react somewhat differently to what are seemingly the same situations. The remarkable thing, then, is that there are any general principles at all!
