Control Theory

Careful observers of humans and other organisms noticed long ago that certain variables that should vary as environmental conditions change actually do not vary much within the organism. For example, store shelves remain stocked despite customers buying products. Control theory arose as one explanation for the mechanism that keeps variables stable. Industrial and organizational psychologists find the explanation provided by control theory very useful for conceptualizing and understanding a great number of work-related phenomena.

The specific mechanism described by control theorists contains three parts:

• 1.
  A function that translates the state of some variable (e.g., the state of stock on shelves) into a perception or signal that can be compared with a desired perception or reference signal (e.g., fully stocked) represented within the organism
• 2.
  A second function that does the actual comparison, subtracting one signal from the other
• 3.
  Positive differences from the second function, called the error signal, that are then passed to the last function, which translates the error signal into actions (e.g., restocking shelves) on the variable in question

If the control mechanism is operating properly, the actions bring the variable in line with the desired perception of that variable. That is, the actions reduce the discrepancy (i.e., error) between the perception of the variable and the desired state of the variable. As a result, the variable remains near the desired level despite outside influences, called disturbances, on the variable.

Anyone who has studied psychology is likely to be familiar with this mechanism as it applies to physiological variables such as hunger and thirst control. In this context, the term homeostasis is generally used to refer to the sameness (homeo) in state (stasis) of a variable over time. Others might be familiar with the concept through engineering circles. For example, it is the mechanism underlying temperature control systems in your home, as well as the systems that make “smart” appliances work, such as cruise control in automobiles or the popcorn setting on microwave ovens. In this context, one might hear the term cybernetic—a term coined by the mathematician Norbert Wiener, who described the mechanism formally with mathematics—or negative feedback loop (because the process reduces the error signal). Within the context of industrial and organizational psychology, all of these terms have been used, but the mechanism most often operates within what we call theories of self-regulation.

In psychological renditions of control theory, the basic control system (defined by the three functions [Page 108]described previously) is conceptualized within hierarchies of systems, and it is from this configuration that some of the more interesting phenomena emerge. Specifically, three additional elements are described in these psychological versions:

• 1.
  The “actions” of higher-level control systems determine the reference values for lower-level systems, and the perceptions from lower-level control systems feed into higher-level control systems, allowing them to create more abstract and complex perceptions.
• 2.
  The reference signals can be diverted back to the sending system as a means of anticipating or estimating the effects of the system's actions. Usually this is called a feed-forward process; it is control theory's conceptualization of human thinking.
• 3.
  Some control systems monitor the operation of other systems and act on those systems by changing the three kinds of core functions described earlier. This is control theory's conceptualization of learning.

With these additional elements, control theorists hope to understand a wide range of phenomena in psychology. Likewise, within the field of industrial and organizational psychology, control theory and its variants have been used to address many issues. For example, human factors researchers are interested in the processes by which humans control aspects of their immediate physical environment. Control theory has been used as a significant explanatory tool in that domain. In addition, control theory has been applied to understanding stress and affective processes within work domains. However, control theory's most prominent presence in industrial and organizational psychology relates to motivation and goal-striving behavior within organizations.

...