They not only recognize family under the condition that they see each other from time to time, but they also recognize humans they have been fond of, although they are likely to retain memories of the territories they once inhabited (down to the houses they once cadged food from).
I had a brother and sister, totally wild, who ate next door, but eventually came to eat at my house and slept anywhere they could find in the tool shed or on the big porch. I sometimes tried a small pat on their heads when they were eating, but that was all. After a year, the female (Tipper) wandered off and I saw her at various houses and bottom up in various dumsters in the neighborhood for years after. The male, however, decided after that year to stay with me, and, having made a clear choice to stay instead of following his sister, he gradually became a very sweet in-door cat. About 3 years later, he suddenly decided to go and wander with his sister, which he did for 2 years. Both cats, however, always ran up and rubbed my ankles when they happened to see me in the street.
Suddenly this winter, the male cat came in through the cat's window and reclaimed his place on one of the bookshelves and became, again, a house cat. He does not follow his sister anymore, but occasionally goes up to the fence to touch noses with her, and perhaps the rare times he disappears overnight are spent in her company.
I think that cats have instinctive priorities (finding a food source, a safe place to sleep, and a territory within which they can hunt without being in too much danger from dogs or people), and then different cats react differently to relationships. And that is what makes them much like people. Most you can take or leave, and you forget the names and even the faces after a few years if you don't keep the relationship alive. But most of us have a small number of cherished friends who we remember even if we have not been in touch for many years. There is some kind of chemistry that flows in good and lasting relationships. And my own observation says that it is the same with cats, and that researchers are wrong when they say that cats don't have long memories.