Maybe you can’t help who you love, but you sure can be influenced by biology. Human beings show strong signs of assortative mating—i.e., being attracted to people with similar physical, social, and psychological traits—so it’s no surprise that many spouses are similar in many ways. The strongest links? Social and demographic traits, like age, height, overall attractiveness and political leanings. Not to mention how likely you are to wind up in church on any given Sunday. It has also been suggested that imprinting—the process of memorizing your parents’ faces as a child, and then applying it to mate selection—may guide assortative mating as well. Put simply, our brains help us “imprint” our parents’ faces as little babies, so when we find our mate-match later in life, they likely resemble our parents (who look like us). Voila, another road to assortative mating!