Marriage. Increasingly, it is something that the well-educated are more likely to do than those with less education. US Census Bureau data bears this out: 62% of Americans with college degrees are married.
But research from my annual survey of museum-goers indicates that 73% of college-educated museum-goers are married ... that's a pretty big jump from the college-educated 62%.
Why are museum-goers even more likely to be married? To be honest, I'm not sure. Maybe it has something to do with a greater inclination towards learning making someone more "marriageable." (I kind of doubt it, but maybe.)
Or, more likely, maybe people who are married are more likely to go to museums. After all, most people visit museums in pairs, families, or groups, not solo. Thus, planning a trip to a museum can be a spur-of-the-moment "what are we doing today?" activity with a spouse versus an outing that takes more planning with a friend.
Turning that around, that also means there are a lot of unmarried adults that might be more engaged with museums if they had someone to go with.