In a relationship, there are many things that attract you to your mate. For example, a sense of humor ranks high on people's list of must-haves for a potential mate. Compatibility is determined by multiple factors, one of which is your age difference. Is it important to consider the impact a significantly older or significantly younger partner's age might have on you? Probably so. A 2010 study of heterosexual couples with age differences indicated that the greater the age difference - older or younger - the lower the wife's life expectancy. On the other hand, men who marry younger women live longer; those who marry older women do not. One explanation for the difference is that younger spouses can serve as caretakers later in life for their older mates.