The Effects of Ability Homophily on Individual Performance

Homophily is the sociological term for a principle that is easily observed and understood: similar people tend to associate with one another (or the well-known saying Birds of a feather flock together ). Homophily creates divides among people with numerous demographic characteristics and causes people to surround themselves with others who are similar to themselves (McPherson et al., 2001). Race and ethnicity have the greatest influence on relationship choices followed by age, religion, education, occupation, and gender (McPherson et al., 2001). While studies of homophily of race and gender are quite common, few studies have examined homophily based on instrumental attributes such as a person\u27s ability or intelligence. Most of the previous research on homophily related to ability comes from educational researchers. Homophily of ability could lead to grouping of people who have similar performance levels. Grouping by ability is of interest because it has been linked to increased performance in experiments involving undergraduate (Goethals, 2001) and primary (Lou et al., 1996; Tieso, 2003) school students. However, previous studies have not examined the consequences of ability grouping when it results from homophily occurring naturally rather than being imposed by a researcher or teacher. To determine if performance benefits are associated with ability homophily, a longitudinal study was conducted to measure the advice and friendship relationships of 404 adults in a military management training course. Performance was measured by an end-of-course formative test, instructor evaluations, and peer evaluations. The results confirm that ability homophily in advice relationships is related to increased performance. Ability homophily among friendship relationships was not related to increased performance