27 Jan 2012  Working Papers

Discretion Within the Constraints of Opportunity: Gender Homophily and Structure in a Formal Organization

Executive Summary — Research has demonstrated that people associate most with others who are similar to themselves, including others of the same sex. What are the implications of such patterns for organizations? This study, written by Adam M. Kleinbaum, Toby E. Stuart, and Michael L. Tushman, offers evidence of how and by whom formal lateral structures serve to link together an otherwise siloed organization. Analyzing millions of e-mail interactions among tens of thousands of employees of a single large firm, the researchers find that it is women more than men who tend to bridge formal structural boundaries in organizations. Thus women play a potentially valuable role in creating ties throughout an otherwise siloed multidivisional corporation. Despite the influence of a firm's formal organizational structure, people often have plenty of discretion to exercise choice. Same-sex interaction results from discretionary choice within the boundaries of the firm's opportunity structure. These results suggest (but do not prove) that same-sex interaction especially by woman can help to span formal organizational boundaries that are otherwise difficult to traverse. The findings raise questions for future research about whether conventional wisdoms regarding gender differences in social network structure remain accurate in current-day organizations. Key concepts include:

  • There are significant differences in how gender interacts with organizational and geographic boundaries to influence individuals' tendency to communicate with members of their same sex.
  • In the large company under study, men engage in same-sex interaction within the opportunity structure created by organizational structure, while women tend to connect with other women who are outside their business units and offices.
  • It is business unit and office boundaries that most strongly influence the opportunity set of potential interaction partners for organizational actors.
  • One of the conventional wisdoms is that same-sex interaction among marginalized people tends to reinforce the stratification of power in organizations. But these findings suggest that communication among women could serve to reinforce, not undermine, their positions in the organization.


Author Abstract

Homophily in social relations is widely documented. We know that homophily results from both individual preferences and uneven opportunities for interaction, but how these two mechanisms interact in formal organizations is not well understood. We argue that organizational structures and geography delimit opportunities for interaction, but that within the opportunity sets created by business units, job functions and offices, actors have a greater level of discretion to choose their interaction partners. Therefore, we expect to observe more homophilous interactions within these structures than across their boundaries. We test this argument using a dataset consisting of millions of e-mails exchanged among thousands of employees in a large information technology firm. We find significant interaction effects between being of the same sex and being in the same business unit or same office on dyadic communication rates, though not with same job function. In an extension, we find that men's communication patterns are consistent with this theory, but that women communicate differently: relative to male-male and male-female pairings, female-female interactions are much more likely to occur across organizational boundaries. These findings have implications for research on homophily, gender, and formal and informal structure in organizations.

Paper Information