Students who take a course in the psychology of learning are usually pretty knowledgeable about learning by the time they have reached this point. Through instruction and on-the-job training, they have already picked up numerous everyday, commonsense principles about how to learn. Students can readily tell their instructors that it is better to spread studying over several days rather than to cram it all into one day (what psychologists call the spaced versus massed practice effect), and that temporary forgetting for otherwise well-known information occurs, especially on exam days (what we otherwise call retrieval failure). Students are aware of what psychologists call context-dependent learning, that it is better to study in the place in which you will take the test. These practical principles are accurate as broad generalities, but they are also only partially true. They are half-truths. This is a book full of half-truths.
Let me quickly explain what I mean. There are numerous facts, laws, and principles of learning that have been uncovered over the past 120 years that psychology has formally been in existence. However, these principles are more complex than the simple statements we popularly use to describe them (e.g., spaced practice is better than massed practice). Statements of these principles almost always require qualifiers; they are true under certain conditions. In this book, I will attempt to tell both halves, and thus in the end something closer to the truth as we know it now.
Take some well-known popular generalizations. Spaced practice produces better learning than does massed practice. Well, yes, usually. But much depends on what we are attempting to learn and how long we will have to retain it, just two of several possible qualifiers we might add here. Actually, one line of research on remembering people’s names suggests that it is better to mass repetitions of a given name at first, and then gradually lengthen the interval between successive presentations (Landauer & Bjork, 1978).1
Repeat the new name immediately; repeat it again after a little while; and keep increasing the interval to the next repetition. As a second example, common sense seems to say that feedback is more effective when it is given immediately and consistently after each performance of a behavior. Yet, this is not always so. Skilled movements are sometimes learned better with delayed or only occasional feedback (see Chapter 11
Other forms of learning pose questions that have alternative correct answers. Do subliminal audio messages, such as suggestions to induce self-control or weight loss, work? Both yes and no answers can be defended. Some data indicate they are effective, but more probably due to a placebo effect. Does this mean that there is no such thing as subliminal learning? No, learning can occur at many levels of awareness or consciousness. Does sleep learning occur? Instead of buying the hard-copy version of this text, should you get the audio version to listen to throughout the night? The answer depends on what you mean by learning. Research conducted in sleep labs indicates that factual information is probably not being learned, but possibly some other forms of learning (such as conditioning of the Pavlov variety) might occur.
The point of these examples is to give a sample of what real principles of learning look like. The goal of this book is to present a scientifically accurate and sophisticated view of the principles of learning. And this includes the qualifying statements: when a given principle holds and when exceptions occur. We can simplify a description to aid comprehension, but it can be simplified only so much before it becomes inaccurate.
The field of research broadly described as learning has its origins in philosophy and science. In particular, the philosophical movements of empiricism and rationalism in the seventeenth and eighteenth centuries, and the development of evolution theory within biology in the nineteenth century, fostered an interest in the scientific investigation of learning. These movements are active influences in contemporary psychology.
The nature–nurture question, which asks how we are affected by biology on the one hand (i.e., nature) and by environment on the other (i.e., nurture), has long been a source of literary, political, and scientific speculation. If a child were raised in isolation from others, what would that child know? Would the child grow to be kind and just, or cruel and selfish? The philosopher Rousseau thought that “noble” peoples would be discovered living beyond the reach of the degrading influences of civilization. However, the discovery feral children, living apart from other humans, were intellectually and emotionally disabled (Candland, 1993).
The area of philosophy known as epistemology studies how we come to have knowledge. This is also the central question for the field of learning. The philosopher Descartes, while not denying that we learn, said that some knowledge is innately given, for example, our ideas of God, infinity, or perfection. This belief is known as nativism. Other knowledge is derived by reason, logic, and intuition, as illustrated by the derivation of geometric axioms and algebraic logic. This source of knowledge is known as rationalism. In each case, knowledge is present independent of particular experiences with the world (Descartes, 1641/1960).
By contrast, the British philosopher John Locke (1690/1956) said that the origin of knowledge is in experience, as provided to the mind through the senses. This is the notion of empiricism
. For instance, our notion of cause and effect derives from our frequent experiences in which one event in the world is regularly followed by another event. What are the origins of our mental associations, such as from STOP to GO or TABLE to CHAIR? Locke said they derive from frequent contiguity: They occur close together in time or space. Therefore, their ideas are also contiguous in our minds.
The influence from empiricism led psychologists to investigate how we acquire knowledge through environmental experiences, and also made them receptive to the study of association learning. For example, how could a dog come to associate two stimuli? By using Pavlov’s method of conditioning, experimenters could pair a tone with food several times, and then look for changes in the dog’s reactions to the tone. Here we see the associative principles of contiguity and frequency.
Nineteenth-century advances in the sciences also influenced the field of learning. One of the most significant influences was Charles Darwin’s On the Origin of Species, published in 1859. Darwin’s theory of evolution described how organisms change over generations in order to better adapt to the environment to which they are exposed. Darwin first noted that there were differences among members of a species; not all individuals were identical. Some of these differences increased the likelihood of survival and reproduction. If these differences were inherited, then the evolution of adaptive specializations would occur across generations.
The capacity to learn evolved as an adaptive specialization. Whereas evolution theory at first stressed anatomical changes over generations as a means of adapting to the environment, psychologists emphasized learning as a means of adapting within the organism’s lifetime. In addition, the belief that different species were related through a common evolutionary history suggested that animals other than humans could be studied, with generalizations proceeding in either direction along the phylogenetic scale.
This discussion of philosophy and biology may seem to be of historical interest at best, but each has had a continuous influence on the field of learning. In one contemporary example, the ideas of nativism, empiricism, and evolution are represented in a theory of biological preparedness for learning. For example, language is thought to be a biologically prepared form of learning in humans, something we learn quickly and readily due to our evolutionary history. This is shown by several aspects of human language: its universality; its common developmental progression in children across cultures; the fact that it is readily acquired even in language-poor environments; the possibility that there is a critical period for learning language; and that certain areas of the brain seem dedicated to language (Pinker, 1994). Environment is also essential to language development, determining the particular language we learn and the specific rules of our native language. But the fact that we even learn a language, as complex as this is and as intellectually immature as we are as infants, suggests the existence of a biological predisposition.
Another example of nature–nurture interaction is the theory that evolution has produced several memory systems through which organisms can learn. There may be specialized systems, such as one for song learning in birds or face memory by primates. Other systems might accommodate incremental learning of habits versus the memory for individual moments that so characterizes human memory (Sherry & Schacter, 1987). The point I am making here is that
contemporary theory reflects the nativism of Descartes, the empiricism of Locke, and the evolution theory of Darwin.
Learning is the acquisition of knowledge. Just as the philosophers of epistemology are interested in the nature and origin of knowledge, so also are psychologists. However, psychologists have defined learning both broadly and in a manner amenable to scientific study. Knowledge must be broadly defined to include not just verbal knowledge, but also skills, attitudes, and knowledge or behavior outside conscious awareness. (See Table 1.1
.) So in addition to an intuitive definition of learning, scientific study requires a precise, operational definition of what can be observed as indicators that learning has occurred. Thus, the study of learning is guided formally by an objective definition, as well as informally by the actual practices and interests of the researchers.
Learning may be defined as a relatively permanent change in behavior or behavioral repertoire that occurs as a result of experience. This formal definition specifies what is included under the rubric of learning, and, just as important, what is to be excluded. This definition has several components.
First, learning involves an observed change in behavior. The point here is that the detection of learning requires some objective evidence. Learning and memory themselves are not observed directly; they are processes that occur in the nervous system. As much as we may be interested in the inner workings of the brain or mind, we often need to observe the organism’s behavior in order see what is going on inside.
Certainly, researchers are coming closer to detecting the neural basis of learning. For instance, PET scans show which brain regions are active when we remember (Raichle, 1994). But each instance of learning and remembering involves nervous processes that are as yet undetectable. Learning and memory are therefore treated as hypothesized theoretical processes that intervene between the environment (which we can manipulate) and behavior (which we can measure).
|The everyday use of the term learning does not describe all of the diverse phenomena that psychologists study in the field of learning. Hillner (1978, pp. 1–2) presented a list of some of what is included by the term: |
|1. ||Learning encompasses both animal and human behavior. It is applicable to the behavior of intact or whole organisms, and even to the adaptive behavior of inanimate model systems such as computer simulations. |
|2. ||Learning involves events as diverse as the acquisition of an isolated muscle twitch, a prejudice, a symbolic concept, or a neurotic symptom. |
|3. ||Learning includes both the external responses of the organism and internal physiological responses. |
|4. ||Learning is concerned with the original acquisition of a response or knowledge, with its later disappearance (extinction), its retention over time (memory), and its possible value in me acquisition of new responses (transfer of training). |
|5. ||Learning is related to such nonlearning phenomena as motivation, perception, development, personality, and social and cultural factors. |
|6. ||Learning deals with the behavior of the average subject and with individual differences among people. |
|7. ||The study of learning is associated with a long academic and scholarly tradition but also serves as a source of practical application and technology. |
|8. ||The learning process is continuous with the more general linguistic, cognitive, information-processing, and decision-making activities of the organism. |
What kinds of behaviors can we use to measure learning? Learning outcomes are multidimensional. Consider an experience you may have had as a child: a sibling jumping out of a darkened
room or closet in order to scare you. The fear learned from such an episode could be expressed verbally
in your recollections of the event years later; physiologically
by increased heart rate in fearful anticipation of a repeat of the episode; and behaviorally
by the avoidance of entering dark hallways or rooms in the house.