Online exogamy

What is endogamy?

The tendency to marry within one's own social group (e.g., same race, religion, or class). It maintains social boundaries and reinforces group cohesion.

What is exogamy?

marriage between people of different social groups - indicator of openness

Online exogamy

Marriage or long-term partnerships between people from different social groups (e.g. race, religion, education) that are formed through online romantic sources.

Endogamy

The tendency for people to form romantic relationships with others who are socially similar to themselves.

Assortative mating

The process by which individuals select partners who are similar to them on socially significant characteristics such as race, education, religion, or age.

Exogamy

Romantic pairing across social boundaries, such as interracial, interreligious, or cross-educational relationships.

Central research question of the study

Whether couples who meet online are more or less socially diverse than couples who meet offline, and how this affects population-level patterns of assortative mating.

Key paradox examined in the paper

Although online dating expands access to diverse partners, it may simultaneously reinforce homophily and social sorting.

Structurally-induced homophily

Similarity in relationships produced by social structures (e.g. segregated neighborhoods or institutions) rather than individual preferences.

Choice homophily

Similarity in relationships that results from individuals actively preferring partners who are socially similar to themselves.

Mating market dynamics

Processes through which competition, desirability hierarchies, and settling behaviors produce assortative mating even without explicit homophily preferences.

Hypergamy principle

The idea that people seek partners with the highest possible social status, leading to sorting by status when competition is intense.

Expanded opportunity structure (online dating)

The Internet dramatically increases the number and diversity of potential romantic partners by reducing geographic and social barriers.

Why expanded dating pools do not guarantee diversity

Larger pools can allow individuals to more easily satisfy homophilous preferences, potentially increasing endogamy.

Structural uniqueness of online romance

Online interactions can occur independently of offline social networks, reducing third-party interference from family and friends.

Third-party interference

Influence from family, friends, or social networks that shape or restrict romantic choices.

Thin mating markets

Situations where individuals face limited offline romantic opportunities due to age, sexual orientation, race, or other factors.

Groups most affected by thin markets

Same-sex daters, middle-aged individuals, divorced people, and many Black women in the U.S.

Self-selection into online dating

The idea that people who are more open to diverse relationships or who face limited offline options are more likely to search for partners online.

Why self-selection does not fully explain results

The study controls for demographic and geographic factors and finds consistent online effects even after adjustment.

Online venue differentiation

Different online spaces (dating sites, apps, games, chat rooms, social media) structure interaction differently and may produce different assortative outcomes.

Dating sites vs other online venues

Dating sites emphasize explicit romantic matching and sorting, while other online spaces often involve incidental or interest-based interaction.

Interface-induced endogamy

How platform design (profiles, algorithms, visible demographics) can encourage sorting based on similarity.

Checklist mentality

The tendency for online daters to evaluate potential partners using explicit traits (age, education, religion), increasing assortative mating.

Role of matching algorithms

Algorithms typically match users based on similarity, which can unintentionally reinforce social boundaries.

HCMST survey

The How Couples Meet and Stay Together survey, a nationally representative dataset used to study how couples form in the U.S.

Survey years used

2009 and 2017.

Why the HCMST is unique

It includes detailed, open-ended data on how couples met, allowing precise classification of online vs offline origins.

Definition of online-formed couples (broad)

Couples who indicated any role of the Internet in their initial meeting.

Purely online couples

Couples who met as strangers online with no prior offline social connection.

Hybrid online/offline couples

Couples whose meeting involved both online and offline elements, such as reconnecting or being introduced by friends online.

Online dating sites/apps category

Couples who met through platforms explicitly designed for romantic matching (e.g. Match, eHarmony, Tinder).

Other online category

Couples who met through non-dating online spaces such as games, chat rooms, or online communities.

Key outcome variables studied

Race/ethnicity, religion, education, age, politics, and mother's education.

Local diversity controls

Measures of racial, educational, and religious diversity in respondents' zip codes and metropolitan areas.

Why controlling for geography matters

More diverse places could falsely make online dating appear more exogamous if not accounted for.

Main racial finding

Couples who met online are significantly more likely to be interracial than those who met offline.

Main educational finding

Online-formed couples are more likely to differ in college degree status.

Main religious finding

Online-formed couples are substantially more likely to be interreligious.

Political assortativity finding

Meeting online does not significantly affect political homogamy or exogamy.

Mother's education finding

No significant difference between online and offline couples.

Age assortativity finding

Couples who meet online—especially through dating sites—are more similar in age than offline couples.

Which online venues increase age similarity most

Dating websites and apps.

Which online venues increase racial diversity most

Non-dating online spaces.

Why dating sites increase age homogamy

Age is highly salient and sortable in dating interfaces.

Population-level effect of online dating

Online dating contributes modestly to increases in exogamy but is not the sole driver of long-term trends.

Counterfactual analysis

Estimating what couple diversity would look like if online dating had never existed or had expanded more rapidly.

Key conclusion about Internet impact

Online dating increases the odds of diverse pairings at the individual level but has limited direct effects at the population level so far.

Most important mechanism identified

Expanded opportunities change baseline probabilities of meeting socially different partners.

Why online dating is still sociologically significant

Even small individual-level effects can accumulate as online dating becomes the dominant mode of couple formation.

Overall conclusion

The Internet weakens some social boundaries in romance while reinforcing others, depending on platform structure and social dimension.