Human behavior is commonly viewed as motivated from within by various needs, drives, impulses, and instincts. In psychodynamic theory, for example, human behavior is the manifestation of the dynamic interplay of inner forces, most of which operate below the level of consciousness (Freud 1917, 1933). Since the proponents of this school of thought consider the principal causes of behavior to be drives within an individual, that is where they look for the explanations of why people behave as they do. Although this theory has gained widespread acceptance and is deeply entrenched in the public view of human behavior, it has not gone unchallenged.
Theories of this sort are criticized on both conceptual and empirical grounds. The inner determinants are often inferred from the very behavior they supposedly caused, creating interpretive circularities in which the description becomes the causal explanation. A hostile impulse, for example is deduced from a person's irascible behavior, which is then attributed to the action of an underlying hostile impulse.
Similarly, the existence of achievement motives is deduced from achievement behavior; dependency motives from dependent behavior; curiosity motives from inquisitive behavior; power motives from domineering behavior, and so on. There is no limit to the number of drives one can find by inferring them from behavior. Indeed, different theories propose diverse lists of motivators, some containing a few all-purpose drives, others encompassing an assortment of specific drives. If causal propositions concerning drives are to be empirically testable, then drives must be specified by the antecedent conditions that activate them and govern their strength, rather than being inferred from the behavior they supposedly produce.
The conceptual structure of theories that invoke drives or impulses as the principal motivators of behavior has been further criticized for disregarding the complex and changeable patterning of human action. An internal motivator cannot adequately account for marked shifts in a given behavior under differing situational circumstances. When varying social conditions produce predictable changes in behavior, the postulated cause cannot reside mainly in a drive in the organism, nor can the cause be less complex than its diverse effects.
Psychodynamic theory assumes a thorough psychic determinism, but it does not as a rule, postulate definite relationships between the unconscious inner life and human thought and action. In fact, the inner dynamics are said to produce any variety of effects, even opposite forms of behavior. Such formulations are, therefore, not easily testable nor refutable by empirical evidence. While the conceptual adequacy of psychodynamic drive theories could be debated at length, their empirical limitations cannot be ignored indefinitely. They provide ready interpretations of behavior that has already happened, but, as we shall see shortly, they are deficient in predicting future behavior. Almost any theory can explain things after the fact. Findings from research conducted is from other perspectives have underscored the need to shift the focus of causal analysis from internal dynamics to reciprocal causation between personal and environmental factors. Behavior patterns commonly attributed to unconscious inner causes can be in stated, eliminated, and reinstated by varying appropriate social influences and by altering people's ways of thinking. Such findings indicate that the major determinants of behavior arise from transactional dynamics, rather than flow unidirectionally from inner dynamics of unconscious mental functions.
The explanatory power of a psychological theory is gauged in several ways. First, theories must demonstrate predictive theories power. Second, the methods the theories yield must be capable of effecting significant changes in human affect, thought, and action. Weaknesses in theories become readily apparent when they are put to work and can be judged by the results they produce. One can predict and change events without knowing the basis for the successes. So third, theories must identify the determinants of human behavior and the intervening mechanisms by which they produce their effects. But explanations that have no predictive value will be pseudo-explanations. The adequacy of explanation is, therefore, judged largely in terms of predictive accuracy. Psychodynamic formulations have been found wanting on all these counts.