Homophily, explained.
Homophily is the tendency for connected people to be similar on a specified characteristic, arising through preferences, opportunities or other mechanisms.
Why it happens
Twelve nodes form two groups. Same-group connection probability rises from 0.15 to 0.8 as the preference parameter grows, while cross-group probability falls from 0.8 to 0.15 under fixed random draws.
Homophily is the tendency for connected people to be similar on a specified characteristic, arising through preferences, opportunities or other mechanisms.
Read the result
Compare actual edge counts with the supplied connection probabilities. The total number of edges is not held fixed while the preference changes.
A worked example
Change a mechanism that favours similar-group links
Inspect the twelve nodes in two groups of six at an intermediate preference.
Increase preference while preserving the random draws and compare within-group and cross-group links.
Distinguish the stipulated preference mechanism from an inference about why a real observed network looks similar.
OPTIONAL DEEPER DETAILGo deeper: inside the model
Inside this model
Twelve nodes form two groups. Same-group connection probability rises from 0.15 to 0.8 as the preference parameter grows, while cross-group probability falls from 0.8 to 0.15 under fixed random draws.
Where this idea is useful
A practical use
Distinguish an observed network pattern from an explanation based solely on personal preference.
A common misconception
“Similarity among friends must be caused by an active preference for similar people.”
Shared settings, geography and institutions can also shape opportunities for contact; a network pattern alone does not identify one mechanism.
What this explanation leaves out
- The supplied linking rule is one possible mechanism, not an identified cause in real data. Total edge count can change; geography and institutions are omitted.
Why does the number of links change with the slider?
The model changes within- and cross-group probabilities rather than rewiring a fixed number of edges.
What opportunities to meet were available before you attributed a network pattern to preference?
Associated thinkers
Associations marked provisional are awaiting source review.
Further reading
Explore the original research or the teaching reference behind this experiment.