Loose ties have traditionally played a key role in meeting partners. While most people were unlikely to date one of their best friends, they were highly likely to date people who were linked with their group of friends; a friend of a friend, for example. In the language of network theory, dating partners were embedded in each other’s networks.
Indeed, this has long been reflected in surveys of the way people meet their partners: through mutual friends, in bars, at work, in educational institutions, at church, through their families, and so on.
Online dating has changed that. Today, online dating is the second most common way for heterosexual couples to meet. For homosexual couples, it is far and away the most popular.
That has significant implications. “People who meet online tend to be complete strangers,” say Ortega and Hergovich. And when people meet in this way, it sets up social links that were previously nonexistent.
The question that Ortega and Hergovich investigate is how this changes the racial diversity of society. “Understanding the evolution of interracial marriage is an important problem, for intermarriage is widely considered a measure of social distance in our societies,” they say.
The researchers start by simulating what happens when extra links are introduced into a social network. Their network consists of men and women from different races who are randomly distributed. In this model, everyone wants to marry a person of the opposite sex but can only marry someone with whom a connection exists. This leads to a society with a relatively low level of interracial marriage.
But if the researchers add random links between people from different ethnic groups, the level of interracial marriage changes dramatically. “Our model predicts nearly complete racial integration upon the emergence of online dating, even if the number of partners that individuals meet from newly formed ties is small,” say Ortega and Hergovich.