ABSTRACT
In our species, children need considerable parental investment for a prolonged period of time before they are able to become independent. The heavy cost of this investment requires the involvement of both parents in raising children; so, selection forces have shaped most human morphs to be predisposed to form long-term intimate relationships in which children can be born and raised to sexual maturity. These long-term relationships are typically called marriage. Accordingly, a successful marriage is a marriage which increases the fitness of the parties involved, predominantly through providing the conditions for raising children with good chances of survival and reproduction. Thus, how successful your marriage is makes an important difference to your fitness and your ratio. Accordingly, the purpose of this chapter is to employ the evolutionary perspective in order to derive insights that can be useful for establishing and keeping a fitness-increasing marriage.
