I'd also be curious to see how the conclusion holds up if you add in the variable of whether they met in college or not. Your pool of people is much more controlled if you go to a University that is more technical than liberal arts and vice versa - it's harder to meet an engineering student at Carolina for example. I guess you can say the same about once you get out into a place of employment - it's harder to meet an engineer if you are a doctor in a hospital. But I do think it would be interesting.