Social Capital Lab

Where in the world do people form cross-gender friendships? We analyzed over a trillion social ties between Facebook users to study the "Cross-Gender Friending Ratio" (CGFR) across nearly 200 countries and territories.

The Social Connectedness Index (SCI) quantifies the relative probability that two individuals from different geographies are Facebook friends, providing a large-scale measure of social ties across regions.

Today’s friendship links from Bakersfield, CA extend all the way to Oklahoma. Why? The Dust Bowl pushed Oklahoma and Arkansas families west in the 1930s. These “Oakies” shaped Bakersfield, inspired the Bakersfield Sound, and left behind ties that still connect them today.

The Illinois Central Railroad carried Black Southerners from the Mississippi Delta to Chicago during the Great Migration. A century later, the SCI shows those same Delta counties remain some of Chicago’s most over-connected distant communities today.