Who is most likely to graduate from college? Gay? Bi? Straight? Men? Women?

Did it seem like a lot more of your friends were earning their degrees this year?  Rainbow tassels and sashes were present at many college graduations this May and there's a reason for that.  Gay / bi men are graduating at a higher rate than their fellow female sexual minority and higher than both of their straight counterparts. 

Leigh Fine wanted to know whether the college graduation rates of gay, lesbian, and bisexual men and women reflected what we see in general.  His respondents were 30 years old, on average — that is, old enough to have passed the age where most Americans complete their education — and they self-identified as non-heterosexual. - businessinsider.com

In order to get more realistic results, surveyors polled people like myself, individuals that were more settled in their lives than recent college graduates.  My 20th college class reunion will be next year and I would like to think I'm doing a littler better now than in 1996.  I'm comfortable with my sexuality, I'm out, have a good place to call home, I have a good career, and I blog part time for a super gay magazine and I'm working on my PhD.  I'm content.  Researchers realized that not only may it take time for people to earn their degree, but it may take others longer to become comfortable with themselves.  The graph below shows the results of Fine's research.

So if you're headed off to college, maybe you should consider majoring in the male anatomy since lesbians and straight men don't do as well.  Are we smarter?  Does having sex with men make us more intelligent than our counter parts?  Are we more driven (no pun intended) than straight men and lesbians?  Wait, is there a difference in our brain structure? (I'm putting my money on this).  
 
There's no explanation for these results as of yet, but do you believe these numbers to be true?  Do you think we are smarter than #1 and #4?  Or is it a difference in drive and commitment that lead us to obtaining our goals?   Or do we just love answering surveys more?
 
Tell us your thoughts.