Abstract
Barnard was acutely aware of the social factors present in organizations and their influence on the effectiveness of organizations. He realized that cooperation, and more specifically that systems of cooperation, were a critical, essential element of effective organizational functioning. This paper extends Barnard's conception of cooperative systems into what we call the coworker effect. The coworker effect is as an important factor linking positive individual behavior with the broader social context of the work group. In this article we will discuss the outcomes of the coworker effect and the sources that give it its power. In so doing, we can show how cooperative systems behaviorally impact on organizations and how organizations might be able to marshal this important resource more effectively.