Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Relationship Formation02:12

Relationship Formation

What do you think is the single most influential factor in determining with whom you become friends and whom you form romantic relationships? You might be surprised to learn that the answer is simple: the people with whom you have the most contact. This most important factor is proximity. You are more likely to be friends with people you have regular contact with. For example, there are decades of research that shows that you are more likely to become friends with people who live in your dorm,...
Friendships and Close Friendships01:20

Friendships and Close Friendships

Friendship formation is a dynamic process shaped by psychological, cultural, and social factors. Friendships play a crucial role in emotional well-being, social development, and personal identity from childhood to adulthood.Childhood and Early FriendshipsFriendships in childhood often arise due to shared environments, such as school or neighborhood interactions. At this stage, proximity and common interests serve as the primary basis for connection. As children grow, their friendships evolve...
Social Relationships and Well-Being01:30

Social Relationships and Well-Being

The significance of social relationships in psychological well-being is a well-established area of inquiry within social psychology. Research consistently demonstrates that the presence of meaningful, supportive relationships enhances emotional health, while the absence or deterioration of such connections can contribute to psychological distress. Relationships serve as a foundation for emotional support, identity, and social belonging, all of which are critical to an individual’s overall...
Spearman's Rank Correlation Test01:20

Spearman's Rank Correlation Test

Spearman's rank correlation test, also known as Spearman's rho, is a nonparametric method for assessing the strength and direction of association between two variables. This test is particularly valuable when the data distribution is unknown or when the assumption of normality does not hold. Named after the English psychologist and statistician Dr. Charles Edward Spearman, it serves as the nonparametric counterpart to Pearson's correlation coefficient.
Spearman's test calculates correlation by...
Genome-wide Association Studies-GWAS01:11

Genome-wide Association Studies-GWAS

Genome-wide association studies or GWAS are used to identify whether common SNPs are associated with certain diseases. Suppose specific SNPs are more frequently observed in individuals with a particular disease than those without the disease. In that case, those SNPs are said to be associated with the disease. Chi-square analysis is performed to check the probability of the allele likely to be associated with the disease.
GWAS does not require the identification of the target gene involved in...
Polygenic Traits01:18

Polygenic Traits

When more than one gene is responsible for a given phenotype, the trait is considered polygenic. Human height is a polygenic trait. Studies have uncovered hundreds of loci that influence height, and there are believed to be many more. Due to the high number of genes involved, as well as environmental and nutritional factors, height varies significantly within a given population. The distribution of height forms a bell-shaped curve, with relatively few individuals in the population at the...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Social network structure and depression by gender in rural Honduras: a cross-sectional study.

BMJ open·2026
Same author

Metagenomic polymorphic toxin effector and immunity profiling predicts microbiome development and disease-related dysbiosis.

mSystems·2026
Same author

Measuring intellectual humility through situated behavior: An alternative to dispositional self-reports.

Behavior research methods·2026
Same author

On the optimal integration of intelligent agents into network systems to steer cooperation.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

Modeling roles and trade-offs in multiplex networks.

Nature communications·2026
Same author

Countering the forgetting of novel health information with 'social boosting'.

SSM - population health·2026

Related Experiment Video

Updated: Jun 5, 2026

Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
14:06

Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays

Published on: November 12, 2012

Correlated genotypes in friendship networks.

James H Fowler1, Jaime E Settle, Nicholas A Christakis

  • 1Division of Medical Genetics, Department of Political Science, University of California at San Diego, La Jolla, CA 92093, USA. jhfowler@ucsd.edu

Proceedings of the National Academy of Sciences of the United States of America
|January 20, 2011
PubMed
Summary

People tend to associate with genetically similar friends, a phenomenon known as homophily. This study reveals genetic correlations in friendships, impacting population genetics and social behavior theories.

More Related Videos

CorrelationCalculator and Filigree: Tools for Data-Driven Network Analysis of Metabolomics Data
07:11

CorrelationCalculator and Filigree: Tools for Data-Driven Network Analysis of Metabolomics Data

Published on: November 10, 2023

Divergence of Root Microbiota in Different Habitats based on Weighted Correlation Networks
09:49

Divergence of Root Microbiota in Different Habitats based on Weighted Correlation Networks

Published on: September 25, 2021

Related Experiment Videos

Last Updated: Jun 5, 2026

Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
14:06

Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays

Published on: November 12, 2012

CorrelationCalculator and Filigree: Tools for Data-Driven Network Analysis of Metabolomics Data
07:11

CorrelationCalculator and Filigree: Tools for Data-Driven Network Analysis of Metabolomics Data

Published on: November 10, 2023

Divergence of Root Microbiota in Different Habitats based on Weighted Correlation Networks
09:49

Divergence of Root Microbiota in Different Habitats based on Weighted Correlation Networks

Published on: September 25, 2021

Area of Science:

  • Social Neuroscience
  • Population Genetics
  • Behavioral Genetics

Background:

  • Humans exhibit homophily, associating with similar individuals.
  • Population stratification is known in genetics, driven by geography or mating.
  • The genetic basis of non-reproductive social associations remains unexplored.

Purpose of the Study:

  • To investigate genetic similarity and dissimilarity among friends.
  • To determine if genotypes correlate due to social associations.
  • To explore implications for population genetics and evolutionary theories.

Main Methods:

  • Analysis of friendship networks using genotype data from the National Longitudinal Study of Adolescent Health.
  • Application of strict controls for population stratification.
  • Replication study using data from the Framingham Heart Study.

Main Results:

  • Friendship networks show clustering of genotypes.
  • One genotype demonstrated significant positive correlation (homophily).
  • Another genotype exhibited significant negative correlation (heterophily), replicated across studies.

Conclusions:

  • Homophily and heterophily operate at the genetic/allelic level in friendships.
  • Findings suggest incorporating friends' genotypes into association tests.
  • Evolutionary theories may need to consider the concept of humans being metagenomic.