I saw this on MyHeritage today – Why Do Couples Often Look Alike?: https://blog.myheritage.com/2020/10/why-do-couples-often-look-alike/. The article is much longer, but went with some highlights.
By Esther October 25, 2020 Family History
When looking through your old family photos and enhancing the facial features with the MyHeritage Photo Enhancer, you might have noticed an interesting phenomenon. There is often resemblance not only between family members who are genetically related to each other, but also among couples — who, in most cases, aren’t genetically related at all. In many cases, these similarities only seem to increase as the couple gets older.
Why would a couple resemble each other if they haven’t inherited the same DNA?
This phenomenon has actually been studied in a variety of contexts, and basically, it comes down to two different factors: how we select a romantic partner, and how that partner influences us.