This proposal is intended to examine human trustworthiness as a key component for countering insider threats in the arena of corporate personnel security. Employees with access and authority have the most potential to cause damage to that information, to organizational reputation, or to the operational stability of the organization. I am interested in studying the basic mechanisms of how to detect changes in the trustworthiness of an individual who holds a key position in an organization, by observing overt behavior – including communications behavior – over time. Rotter (1980) defines trust as a generalized expectancy held by an individual or a group which the communications of another (individual or group) can be relied upon. In this investigation, “trustworthiness” is defined as the degree of correspondence between communicated intentions and behavioral outcomes that are observed over time (Rotter, 1980 & 1967). The degree of correspondence between the target’s words and actions remain reliable, ethical and consistent, which its degree of fluctuation does not exceed observer’s expectations over time (Hardin, 1996). To be able to tell if the employee is trustworthy is thus determined by the subjective perceptions from individuals in his/her social network that have direct business functional connections, and thus the opportunity to repeatedly observe the correspondence between communications and behavior. This study adopts the concept of correlating data-centric attributions, as observed changes in behavior from human perceptions; as analogous to “sensors” on the network. The Attribution Theory is adopted in the experimental situations (the “leader’s dilemma” game) to extract indirect perceptions of trustworthiness toward a critical worker over time in a group dynamics (Kelley, 1973). The principles of distinctiveness, consensus and consistancy are applied in these experimental situations.