This study sought to examine the relationship between social interaction and tacit knowledge transfer, as a dyadic exchange of critical knowledge between a Subject Matter Expert (SME) and a Knowledge Recipient (KR). Knowledge was defined as information and know-how, not merely as organized data or a system, but an active social process that was perceptually constructed consisting of individual beliefs, values, and assumptions. The primary focus of this paper was to better understand how social interaction influenced critical tacit knowledge transfer, transition, transformation, diffusion, or conveyance within the confined and highly compartmentalized environment of the United States Intelligence Community (USIC). This study examined the evolving and dynamic role social interaction played when the source-recipient dyad socially engaged in an intense problem-solving social dialogue. This study used a qualitative descriptive approach to observe the effects of mutual contact in relation to knowledge construction, sharing, and transfer. A qualitative method with subject interviews was used to collect evidentiary data. This study confirmed that several social attributes, behaviors, and/or actions were highly effective for critical knowledge transfer even when the dyads were constrained by organizational cultures, legal statutes, policies, or other environmental factors. Further examination of the data revealed key themes linking social interaction and increased knowledge transfer rate. For example, the effects of knowledge transfer were particularly evident when dyadic interactions included focused participation, willing cooperation, creative reflection, insightful questioning, or reflective listening. The study results showed that these and other characteristics markedly improved mutual trust, increased resilience and mutual adaptation, and strengthened social cohesion that reduced SME-KR knowledge distance. In effect, these dynamics were shown to be important ingredients for effective and harmonious critical knowledge transfer within the USIC. In summary, this study affirmed six major conclusions revealing key aspects of interaction that reduced obstacles in knowledge transfer. These were: (1) Mutual Trust Increased Tie Strength which Improved the Depth of Knowledge Transfer; (2) Participant Motivation, Attentive Listening, and Ability to Self-express Increased both Quality and Tempo of Knowledge Transfer; (3) The Source-Recipient Asymmetric Structure Impacted the Source Transfer Capacity; (4) Constrained Environment of the Intelligence Community did not Impinge Tacit Knowledge Transfer; (5) Knowledge Sharing Experimentation Sessions using Analogies, Metaphors, or Models were Effective for Tacit Knowledge Transfer; and (6) Working in Close Physical Proximity Increased the Rate of Tacit Knowledge Transfer. These conclusions were drawn after close examination and thematic analysis of the empirical data which were compared and contrasted with historical and contemporary literature findings. This work revealed that individuals were more inclined to collaborate in solving mutual problems if specific social attributes, personal behaviors, and/or actions were present. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]