Actually there are only two undergraduate interns, and one local high school senior. Most of the interns have graduate education.
OK but in addition to the local high school senior, one of last year's summer interns is 17 or just turned 18. (And both were present at the meetup.)
Just a reminder that the July 12th Overcoming Bias / Less Wrong meetup in Santa Clara, CA @7pm will feature Robin Hanson, Michael Vassar, and the Singularity Institute summer interns. This meetup will also take place in a larger house - there should be plenty of room to mingle.