This dissertation contributes to our understanding of how people build and use social capital – resources embedded in social relations – in organizational settings. Whereas the extant literature has tended to focus on the structure of interpersonal networks within organizations and the link to various indicators of individual attainment, this dissertation instead uncovers the dynamics of network action. Two central questions are addressed: (1) During times of organizational change, how do organizational actors use the social resources accessible to them by virtue of their position in the structure? and (2) What organizational interventions can help people forge valuable new connections in the workplace? Core to this investigation is the concept of social capital activation – that is, the conversion of latent social ties into active relationships.

Three empirical studies illuminate different facets of social capital activation during commonly experienced forms of organizational change: (1) an organizational restructuring; (2) large-scale transformations that create individual-level threat or opportunity; and (3) the introduction of a novel employee cross-training program. Because organizational change is often accompanied by significant shifts in resources and power, network activation choices in these periods can have significant consequences for individual attainment and organizational performance.

The dissertation draws on unique data from three disparate settings – a global information services firm; a large health care organization; and a software development lab based in Beijing, China. Multiple research methods, including a large panel data set of archived electronic communications, qualitative interviews, experimental studies conducted with samples of working professionals, and a longitudinal field experiment, are used to identify how organizational actors marshal social resources through individual-level network activation choices.

Findings from these studies contribute to research on: (1) organizational social capital; (2) the structural dynamics of organizational change; (3) ascriptive inequality in organizations; (4) cognition and social networks; and (5) workplace practices and network change.