In 1993, the U.S. government funded a study to see why the head of a penis was larger than the rest of it.
After one year and $1.8 million dollars they concluded that the head was bigger than the shaft to give the man more pleasure during sex.
After the U.S. published their findings France decided to do their own study. After 3 years of research and $2.7 million dollars, they concluded that the head was bigger to give the woman more pleasure during sex.
The U.K., unsatisfied with these findings, funded their own study. After 2 weeks and approximately $85, they concluded that the head was bigger to keep a man's hand from flying on and smacking him in the forehead.