Researchers from the University of British Columbia had 1000 adults rate hundreds of photos of members of the opposite sex for sexual attractiveness. In the images, the models displayed a wide-range of facial expressions and poses.

The researchers found that the women rated the photos of men who appeared happy least attractive, while they were turned on by men who appeared prideful, moody, and even shameful.

On the other hand, the men in the experiment were most sexually attracted to the photos of women who smiled and looked happy.

I don't know if I believe this study, or not.  We know that women want a happy, positive, responsible man.  But they don't want one that smiles?  That makes no sense.

And honestly, have you ever known a woman to be turned on - from her man acting like a complete jerk?  No, I haven't either.

I think that the women attracted to guys that DON'T smile, are just used to dealing with guys that are not very pleasant, period.

I say smile.  The more smiles in the relationship, the better.