I will reveal what a terrible person I am in this post. :P In my earlier gens when they don't have so many upgrades and have to work a lil harder for their money, I'm awful about working more with the one who has the highest salary to improve their health the most. In other words, if I don't have the time to train both of them, I want the one with the highest salary to live the longest, so I concentrate on them more. I make sure to train them to work out (or use the treadmill if they can afford it) and check their weight (I love to hear them cheer when they get off the scales.) When there are duplicate fruits or vitamins in the store, I always give them to the person with the highest salary. However evil it may sound, it has always worked for me. So I know for a fact that health is the determining factor in how long they live, not age or gender.

I generally try to choose younger wives though. It's because I want to get the most childbearing years I can out of them. hehe