talking still about network structure and so forth.
We're going to talk a bit about what's known as homophily.
been recognized in human interactions for millenia.
1600. Birds of a feather flock together.
and schools. A whole series of different attributes.
another race, of they, of with they would discuss important matters.
the population is. interracial marriages in the US.
a study by Roland Fryer /g, 1% of, of whites marry outside of white.
should be expected if these things are happening uniformly at random.
High School, Middle School friendship less than 10% of expected.
see at roughly 50% if there was not any bias in that.
here's a picture from[COUGH] a high school in the[UNKNOWN] data set again.
um,[UNKNOWN] so the blue notes are blacks.
things then those nodes would try and collapse it.
So a spring algorith tries to relocate the nodes on the page.
other, and without just collapsing everything to a giant small ball.
52% of the population, yet 86% of their friendships are with other whites.
happening at random and what's actually happening in the data.
different characteristics than larger groups.
but we're we're seeing a, a, a strong segregation pattern.
spent, did at least three activities with another individual in a given week.
stronger relationships because there's more of a, of a hurdle to be crossed.
And the, the network ends up being[UNKNOWN].
think you know, you can see one here, there's one here, one here.
even more segregation and fewer cross group relationships than before.
Now this is not something that's unique to American high schools.
this is a study by Baerveldt et al looking at a Dutch high school.
and here you see, again, you know, the Dutch make up 65% of the population.
79% of their friendships are with other Dutch.
5% For Moroccan's, 27% of their friendships are with other Moroccan's.
larger than the fractions of the population.
course goes along, but it's not just one possible explanation.
It could be that there's opportunities, you know that, that somehow.
involved. there count be social competition.
the structure of the network is characteristic dependant.
impediments in terms of the segregated network.
understand what the structure of networks has to do with behavior.
And it's interesting to understand homophily in its own right.
You know, why are we seeing these patterns?