If the brain is the sexiest organ — size does matter

 
Well this message hasn’t come to you in spam email messages but has implications in your personal life. Scientists have discovered that the amygdala, a section of the brain seems to have an important role in sex drive. This Nature article then goes on to speculate that there is huge market market potential in this discovery "If researchers can nail down the roots of sex drive, they might ultimately hit on drugs that compensate for lack of arousal."
This article via Brainworld who also found the picture, Amygdala Rules by Helen Norton.

Brain size matters for sex.