#1.)  Loud Car Engines.  If you think guys who rev their engines at traffic lights are morons . . . you're right.  But they also might be onto something:

--The sound of a powerful engine has been proven to elevate testosterone levels in women's saliva, which indicates an increase in how aroused they are. 

#2.)  A Deep Voice.  It's not really surprising, but a 2007 study by scientists in the U.S. and Canada proved that men with deep voices are seen as more dominant, healthier, and more masculine.

--And it doesn't just apply here.  According to a sample of 100 men and women living in tribes in Tanzania, men with deep voices fathered the most children.  (???)

#3.)  Cucumbers.  You're probably thinking it's because of the SHAPE, but you're just a pervert because it's actually the SMELL . . . it's been shown to increase blood flow to a woman's nether regions and make her more aroused.

#4.)  Bananas.  Again, it's not because of the shape.  Researchers at Rockefeller University in Manhattan studied female rats.

--And they found that there's a strong connection between sexual arousal and how many potassium ions were flowing to their brains.

(ModernMan.com)