Empirically, home schooled kids are more socially awkward. I have nothing against home schooling, but the kids are definitely more limited in their exposure to different people and situations.
I've not noticed this personally, and have known loads of homeschooled people.
When you say "empirically" though, I'm assuming there some info out there that backs this up? Would love to take a look, as homeschooling is on the table for us.