1. Description of the obstacle

Although psychology is a very heterogeneous science that contains such diverse specialties as psychophysics, radical behaviorism, psychoanalysis, biopsychology, and many others, there is a common set of methodological and ontological assumptions that comprise what we may call the psychological worldview. Similarly, the diverse sociological schools share a common sociological worldview. Because these two worldviews are incompatible, any attempt at forcing the sociological worldview into psychology can be regarded as a disruptive foreign interference. Therefore, sociologism should be seen as an epistemological obstacle to the advancement of psychology (and consequently of physiological psychology).

Before we move to actual examples that will more properly define sociologism and show its obstructive character, the notion of worldview must be elaborated upon. Few people would question that psychology and sociology are distinct sciences. The traditional view is that psychology studies the individual, whereas sociology studies group phenomena. This implies a complementarity between the two sciences, in the sense that knowledge about individual factors can be complemented by knowledge of group factors, or vice versa. Complementarity between psychology and sociology was probably real in the distant past. As the two sciences developed, however, they moved apart and ended up creating not only their own research methods but their own objects of study. Consequently, even when the same word is used to refer to a phenomenon, psychology and sociology may deal with distinct objects. These objects are distinct not because they are two parts of a single entity (as the old conception would want them to be) but because they are totally unrelated objects. Psychology and sociology no longer share the common set of objects and methodologies that they shared in the past. To say it in precise philosophical words, psychology and sociology have distinct onto-gnosiologic grounds.

2. Examples of the obstacle

The incompatibility between psychology and sociology is evident in standard psychological writings. For instance, Jean Piaget wrote a conciliatory paper where he tried to recall productive relationships between psychology and other sciences. Despite his good will, he admited that he was unable to indicate productive relationships between psychology and sociology (Piaget 1979). Another example is the book review wrote by two psychologists about a sociology book: the core of the review is a radical criticism of the fundamentals of sociological analysis of behavior rather than an actual discussion of the specific arguments presented by the author (Lachman & Lachman 1980).

What exactly is the sociological worldview? Let's ask the sociologists. Auguste Comte, Emile Durkheim, and Karl Marx were three of the greatest sociologists of all times. Comte, the father of sociology, argued that the study of social phenomena cannot be treated as a process of deduction based on what is learned from the study of the individual. The reason for this commandment is that social conditions can change the action of psychological laws (Comte 1877). On his turn, Durkheim repeated tirelessly that social phenomena transcend individual consciousness to the same extent that life transcends the inanimate substances which it is made of (Durkheim 1907). Marx was even more explicit and claimed that the causes of human behavior lie on the relations of economic production. Consequently, it is not human consciousness that determines what a person will be; rather, it is this person's social being that determines his/her consciousness (Marx 1911). To say it boldly: in the sociological worldview, the social is a basic phenomenon within which individual behavior can be found only as an abstraction.

Individual behavior has quite a different status in the psychological worldview, as Sigmund Freud and B. F. Skinner will tell us. For Freud, human civilization is possible only by coercing the individuals and repressing their natural impulses (Freud 1928). The social is, therefore, explained by the individual. Society is simply a gathering of individuals. The social is nothing but a by-product of the individual. And Skinner is even more explicit about it. According to him, the great social problems of our times can only be solved by a behavioral technology, that is, a strategy designed to modify the behavior of individuals (Skinner 1975). A non-tautological analysis of behavior must deal with individual organisms rather than groups of organisms even when studying social behavior (Skinner 1972). To say it boldly again: in the psychological worldview, the individual is a basic phenomenon with which the abstract entity called the social can be understood.

The conflict between psychology and sociology is not new, and many people have tried to solve it in one way or another. Four groups of people can be identified. People in the first group believe the opposition exists because psychology has an erroneous perspective. The solution would be to reject psychology in favor of sociology. People in the second group hold the opposite opinion: they believe sociology is wrong and should be rejected in favor of psychology. For people in the third group psychology and sociology constitute two different levels of analysis of the same object. Thus, if there is disagreement, one of the two must be mistaken. The solution would be to reexamine both sides. Finally, people in the fourth group believe that psychology and sociology are antithetical, transitory approaches to human behavior. Some sort of synthesis should resolve the conflict.

Although some psychologists may disagree with me, I think Kurt Lewin is a member of the first group. His concept of social field does not solve the opposition between psychology and sociology; rather, it abandons psychology. Thus, Lewin tell us that the organization of a group is quite different from the organization of the individuals who form the group and that the idea of individual behaviors as individual phenomena is an outdated inheritance from Aristotelian philosophy (Lewin 1935). Other authors share this opinion that sociology is better than psychology. For instance, H. Tajfel refutes Taylor and Brown's (1979) statement that theories in social psychology should seek explanations at the level of individual behaviors and even criticizes them for placing an individualist bias in social psychology (Tajfel 1979). The idea that individualist studies cannot fully explain the complexity of psychological phenomena was put forward by Willems (1977). Now, if the question we are dealing with is the disagreement between psychology and sociology, then sociological arguments cannot answer the question. If we trusted sociology this much, we would have already thrown psychology away and would not be dealing with this issue. Therefore, this first group gives us no real solution to the problem.

McDougall was certainly a member of the second group. For him, sociology can obtain scientific results only if psychology can provide it with valid knowledge about human nature and solid principles for the interpretation of human conduct (McDougall 1950). John Watson taught that psychology is essential for the understanding of society and that sociology should adopt the principles used in psychology (Watson 1925). Gordon Allport remarked that sociologists take the easy approach of building an artificial person with laws of social behavior rather than the hard approach of studying the individual person scientifically (Allport 1937). Now, if the question we are dealing with is the disagreement between psychology and sociology, then psychological arguments cannot answer the question. This second group is as unsatisfactory as the first one.

The members of the third group believe that psychology and sociology are two different ways of looking at the same problem. Taylor and Brown (1979) stated that the use of the individual as the unit of analysis does not imply the denial of social processes but only the acceptance of the principle that psychologists are not concerned with social phenomena. I am sure they would also say that the study of social processes does not imply the denial of individual processes. Newcomb (1978) acknowledged that what distinguishes social psychology from sociology is psychology's constant interest in person-to-person interaction rather than in social phenomena. Chinoy (1961) emphasized that neither psychology nor sociology alone can explain human behavior and that each science provides explanations for some aspects of behavior. However, we face again the problem of legitimacy. If psychology and sociology are the sciences of human behavior, and if they disagree about it, how can a scientific statement be made about the real nature of human behavior? There is no legitimacy in the statement that the two sciences deal with the same object. If we see the same object there, it is because in our common-sense worldview those two objects are really only one. But our common-sense worldview has no authority in science. Scientifically, we do not know whether there are two objects or only one.

Finally, the members of the fourth group think that both psychology and sociology are wrong. They propose the dissolution of the two sciences into a third one. This third science might be a true social psychology (Boutilier et al 1980), a messianic ultimate synthesis of behavioral sciences (Wilson 1977), or a pretense conceptual totalization in the marxist style (Sartre 1976). But, once again, no real solution can be obtained. Any proposal of synthesis that comes from outside of science lacks scientific legitimacy.

After rejecting four proposals for solving the opposition between psychology and sociology, we may wish the opposition did not exist. Does it really exist? Well, if the two sciences have different methods and deal with different objects; if they only appear to share an object (viz., human behavior) because they keep using an old phrase to refer to something totally new; then psychology and sociology are not really in opposition. If psychology and sociology have distinct onto-gnosiologic grounds, then there is no opposition. There is also no real foreseeable gain resulting from an interaction between the two sciences. Consequently, an intrusion of sociological principles into psychology would constitute an undeniable epistemological obstacle to psychology.