The selfish gene or the kind gene? Who knows?
I only knew one of my four grandparents well. Two had died before I was born. I have stiff memories only of my father's father. He was not a warm person and I don't think my father liked him much. Visits were more duty than pleasure. My recollection is that it was all about him and that he hadn't much interest in any of his children. Any time I feel I'm getting a bit self-obsessed, I trace it back to him and remember how unpleasant a trait it is.
My maternal grandmother came to live with us when I was seven and was a member of our household until she died nine years later. When I came home from boarding school she would always be waiting at the front door and I can still recall the emptiness of arriving home the first half term after she died.
She was quite a looker, a good conversationalist, a tireless gardener, and she was very fond of me and we talked. As a 19-year-old, she married a man in his forties and had the happiest of marriages. I can still hear her saying "better an older man's darling than a young man's slave."