In many tribes here in Cameroon (though not all of them) culture dictates what happens to a new widow.  Upon the death of her husband, his brother takes her as his wife.  This is the only instance where the man does not pay the bride price.  The woman's family understands that the man's family has already paid for her.  If the brother already has one or more wives, he just adds his brother's widow to the group.  Polygamy is quite common in many (though not all) tribes, even today.  

We recently learned that in some tribes, polygamy was introduced many generations ago to eliminate the problem of prostitution.  It was thought that if a man had many wives to choose from, he would not stray from home, seeking pleasure outside of marriage. 

Nice theory.  Papa Jim has had it explained to him, in minute detail, exactly what would happen to him if he even entertained thoughts of taking on a second wife.