An amusing study from my abnormal psychology class:

An average-looking male/female went up to students of the opposite sex asked them the following questions:

1. “Would you like to have coffee with me?”
   20% of male subjects said yes
   75% of female subjects said yes
2. “Would you like to have coffee at your house?”
   50% of male subjects said yes
   35% of female subjects said yes
3. “Would you like to sleep with me?”
   90% of male subjects said yes
   5% of female subjects said yes

After reading us these numbers, our Professor quipped saying how all the men in the class were thinking “so I only need to ask 20 girls…”