Albert Einstein might not have been a guy you would want to sit down and have a beer with. He was happiest thinking alone in a quiet room (or entire house). His first marriage sounds quite rocky, although it lasted 16 years and produced three children. His second marriage was to a cousin – a first cousin, their mothers were sisters and she did not have to change her name because it was already Einstein. They did not have biological children, but she had two children from a previous marriage which he adopted. But of course, he is not known for developing any special or general theories of harmonious human social relations.