This is a link from eharmony's dating blog. Since OkCupid hasn't been putting up new statistical blogs lately, I'm left with eharmony's blog, which actually isn't bad advice.
This is an article about the 7 ways dudes scare off women.
A lot of these methods apply directly to nerds including Calling and Texting Her Too Much, Being a Space Invader, Revealing an Odd Hobby or Interest Too Soon, and Bad Manners. The first three that I've listed are from overeagerness and how sometimes geeks don't have a good sense of where to set our boundaries. The last one is probably more scary hygenie than actual bad manners.
I'll probably elaborate more...someday...when I'm not so sleepy...
