You’re out to dinner, and you’re sitting there with a friend. There’s an old couple sitting nearby, and you quickly glance over. Sure, they look cute, but did you also notice how similar they look? There’s always that floating question, “Why do married couples end up looking like each other?” The question was simply answered by researchers at Stanford University, “the reason longtime companions begin to resemble one another may be because they spend so much time mimicking each other's facial expressions. Experts believe all the contortion causes their faces to take on similar shapes.” But is that all? Owners looking like their dogs may have been more easily explained, but just by mimicking someone’s facial expressions year after year you end up looking like them? That’s a hard one to grasp.
Similarities between owner and dog: http://www.maddogproductions.com/ds_dogs_owners.htm
Married Couples, a simple explanation: http://www.boston.com/partners/whdh/3/7healtharchives.html