The tendency to associate with similar others is one of the most established facts in social research. Back in the 1950s, sociologists Paul Lazarsfeld and Robert Merton called it “homophily” (from Greek, “homo”: similar and “philia”: love or affinity. Since then, the evidence documenting this phenomenon accumulates, showing that, indeed, birds of a feather do flock together.
Anybody who had moved to another country or to another company would be very familiar with this phenomenon. Encountering someone from your same country or even more, from your same town, automatically creates a positive disposition towards this person, which may be the foundation of a fruitful professional relationship. Communication flows easily, language is not a barrier, and common references to familiar places are likely to make us feel at ease.
Note, however, that encountering the same people in your home town or country would not be anything special–after all, the place would be full of people like you! It is the context that determines the special character of the encounter. More generally, it is the scarcity of a salient attribute (in this case, the same origin) that makes the other person unique. The same is true for any other attribute that may help define our identity, such as gender, ethnicity, or religion, to name a few.
Although homophily is a well-established fact, we know much less about its consequences for our performance. Does a professional network filled with people like us help or hurt our ability to get things done and advance in our careers? It was precisely the lack of a clear answer to this question that motivated me and my coauthors to investigate the performance effects of homophily.
To do this, we used an innovative method to study the tendency to create professional relationships with similar others (net of other confounding factors such as availability and skill) on the performance of 1,746 professional employees working for a global investment bank in more than 30 countries. We found that homophily helps junior bankers to get established and start moving up the ladder, but hinders the performance of experienced bankers. This difference holds when we use formal criteria to distinguish between “junior” and “senior” (associates versus managing directors) or when we used the informal status in the organization. Again, homophily helps low-status bankers, but it hurts high-status ones.
The mechanism through which this effect operates is straightforward. Junior or low-status employees benefit from the solidarity of similar others, which may compel them to help. Restricting one’s network to similar others is likely to reduce our access to a diverse pool of resources, but this drawback is more apparent than real for people who may not have access (or may not need) those resources, as it is likely the case with junior and low-status employees. Overall, the balance between the gains from enhanced solidarity and the losses from reduced diversity is positive, helping junior employees to perform.
Things are different for senior or high-status bankers. These employees should face few restrictions in accessing resources and getting support from their colleagues. If their professional network is restricted to similar others, they are likely to access a less diverse pool of resources through their network without gaining much in terms of solidarity. The drop in diversity would not be offset by the marginal gain in solidarity. Their performance naturally suffers.
An important implication of these findings is that people may need to renew their networks as they move up in the organization, leaving behind the homophilous network they have in the earlier stages of their career and developing a more diverse and widespread network. This, of course, is easier said than done. In my next post, I will explore when and how people are likely to do it.