I've just finished Richard Feynman: A Life in Science by John and Mary Gribbin. Here are some positive psychology observations.
First, it's clear that Dr. Feynman had a great capacity to love and be loved. He married his high school sweetheart knowing that she had contracted tuberculosis. And he seemed to be able to enjoy time spent with her while she was in a facility near him during the time he was working on the Manhattan project at Los Alamos. In a letter to her written after her death and found among his papers after his, he expressed his deep love for her and how empty her absence made his life. He went on, after 10 years or so, to marry again and have a family that seems to have been important to him and a source of pleasure, engagement, and meaning. In summarizing, the authors write:
Richard Feynman was indeed, as well as being a scientific genius, a good man who spread love and affection among his family, friends and acquaintances. In spite of the dark period in his life after the death of Arline, he was a sunny character who made people feel good, a genuinely fun-loving, kind and generous man, as well as being the greatest physicist of his generation.
In addition to his capacity to love and be loved, he had a great deal of zest. Speaking of that "dark period", the authors note that he was, by his standards, depressed, but that no one noticed. His mentor and friend at the time said, "Feynman depressed is just a little more cheerful than any other person when he is exuberant."
He also appears to have had a real appreciation of beauty and excellence, as he became a highly accomplished drummer and skilled artist.
Finally, Richard Feynman, for all the magic of his mind, clearly had a growth view of "smarts." Being smart was about gaining knowledge and exerting effort persistently toward understanding, things that he took great joy in doing. But, he had his times when understanding did not just blossom in his mind effortlessly. For example, he has recounted how difficult he found solid geometry. For the first two weeks, he just didn't get it. Then he finally realized that the drawings the teacher placed on the blackboard were intended to be of 3-D figures and it clicked. But, had he had a "fixed" mindset, this might well have been enough to convince him he had reached the end of his math smarts.
This growth mindset is also evident in the advice he gave his younger sister, whom he adored. Feynman was in graduate school and his sister, Joan, was 14. She was fascinated by astronomy, but had been told by their mother that the female brain wasn't up to doing science. Feyman gave her a college-level astronomy text and, when she said it was too difficult, he replied:
"You start at the beginning and you read as far as you can, until you get lost. Then you start at the beginning again, and you keep working through until you can understand the whole book."
This is not the advice of a "fixed" mindset person; he did not see difficulty as a sign of "not smart", but as an indication of a need for a new strategy and greater effort. Joan went on to become a respected scientist in her own right. In a further slap at the "entity" view of intelligence, Joan's high school IQ measurement was 124, while Richard's was 123!