Homophily, love of the same

Every individual in a social network has relations to other individuals because of characteristics such as values, education, language, behaviour and so on. Similarities between characteristics in individuals can often affect a connection or tie. People often get their best friends at school, work or other places they spend a lot of time doing activities. This is referred to as a focal point or a organizational foci. The focal point helps the homophily expand in a way that adds edges to the graph of a social network.


In this blog post we’re talking about homophily in sport athletes, particularly football players and their relations to each other.

In a football team, there are always players creating bonds. Most often all the players have an ethical “force” to be friends with everybody in the whole team, but there are also players with especially strong bonds. These seems to be really close friends and connect with each other in another way than with the rest.


To know how these bonds are created, we have to take a look on all the factors that exists outside the football players’ friendship-network.

These factors are called surrounding contexts.


Positioning on the pitch:

A football team’s tactic is built up on the player’s position. A goalkeeper is depending on the defenders to do their job and vice versa. But the goalie has to know how the exact player in the exact position in the defense is most likely to operate

– How will “Mike” tend to act if he gets the ball in different situations.

This will be much easier if they know each other. Because of the placement on the pitch, it is most likely that the goalie connects in a higher “friendship-level” with the defenders than the rest of the clubs players. 



It’s common that players with the approximately same age will become friends. They have a lot to talk about, since they have experienced less/more than rest of the guys. 


Previous football teams and leagues:

Players have sometimes played in a different team, maybe even in a different country. Let’s say there are today two players in Arsenal in England who has also played for Barcelona in Spain. These two players is likely to have already created a knowledge of each other, and maybe they can consider each other as friends.


Players from the same academy:

My new example is two guys that are now playing for Manchester United. They were both youngsters in the clubs’ academy some years ago. One of them stayed, one left to another club for a couple of years. When he now came back to ManUnited – compared to the other players – we can clearly see that these two players had already created a good friendship while they were in the academy. 



Earlier, there was a lot of racism in football. This topic is now much improved, and we hear less and less about incidents related to this. But there will most likely always be someone struggling to behave the right way, so this has to be considered a factor for making friends. Some football players are also playing a role in their national-team. In this way players from the same nation can connect to, and make good friends with players from completely different club-teams. After a club-match, I have many times observed players walk of the pitch acting “best-buds” with some other player from the other team.


With all these factors taken in mind, I will say that homophily in football is something really important for the outcome of the game. There will be formed triangles all over the pitch. The principle of homophily will create several triangles with relationships weighted either strong or weak between the players forming the triangles. If all the players on the team are connected, and with this forms a complete graph, I will say that the managers’ tactic is more likely to work, and the team are more likely to win the match.



Easley, Kleinberg: Networks, Crowds, and Markets: Reasoning About a Highly Connected World, Cambridge University Press, 2010.


Sergio Currarini, Fernando Vega Redondo: A Simple Model of Homophily in Social Networks, [Link:http://virgo.unive.it/seminari_economia/Currarini.pdf] 2011

Wikipedia: Homophily [Link:https://en.wikipedia.org/wiki/Homophily ] 2016