Is it true Feynman's IQ score was only 125?
Feynman was universally regarded as one of the fastest thinking and most creative theorists in his generation. Yet it has been reported-including by Feynman himself-that he only obtained a score of 125 on a school IQ test. I suspect that this test emphasized verbal, as opposed to mathematical, ability. Feynman received the highest score in the country by a large margin on the notoriously difficult Putnam mathematics competition exam, although he joined the MIT team on short notice and did not prepare for the test. He also reportedly had the highest scores on record on the math/physics graduate admission exams at Princeton. It seems quite possible to me that Feynman's cognitive abilities might have been a bit lopsided-his vocabulary and verbal ability were well above average, but perhaps not as great as his mathematical abilities. I recall looking at excerpts from a notebook Feynman kept as an undergraduate. While the notes covered very advanced topics-including general relativity and the Dirac equation-they also contained a number of misspellings and grammatical errors. I doubt Feynman cared very much about such things.
Do you think we will ever find another Einstein?
This is a very difficult question. Einstein was special for many reasons, and was the dominant figure in 20th century physics, if not all of science.
In the modern era many more people have access to advanced education-think of India and China plus all of the developed world. While I believe even an average scientist these days is quite an exceptional person, both in terms of ability and the amount of training he or she has received, it is much more difficult now to stand out in the crowd. Think of the NBA: the average player today is much better than the average player of 50 years ago. Any guard in the league is an athletic freak of nature. But when they play against each other they are relatively evenly matched. It may be a long time before we encounter another giant like Einstein who so far surpasses his contemporaries.
If you are interested in psychometrics and the far tail of cognitive ability, I recommend several of Jonathan's papers, including:
Wai, J., Lubinski, D., & Benbow, C. P. (2005). Creativity and occupational accomplishments among intellectually precocious youths: An age 13 to age 33 longitudinal study. Journal of Educational Psychology, 97, 484-492. pdf