Question: I noticed in the book "A Beautiful Mind", by Sylvia Nasar, that a recommendation letter, for PhD applications, written for John F. Nash runs as follows: *This man is a genius.*

Then, out of curiosity, I wonder that if such reference letters for PhD applications work in the present days? 

Image taken from the [Graduate Alumni Records](http://findingaids.princeton.edu/collections/AC105/c3) of Princeton University:

[![enter image description here](https://i.stack.imgur.com/p7gtk.jpg)](https://i.stack.imgur.com/p7gtk.jpg)

Answer: 
Even though the event that inspired this questions may or may not have actually happened, the question is still a valid one. 

I suspect it greatly depends on who wrote the recommendation. If the person writing that recommendation is a great authority in this field and is known for not giving praise easily, then such a recommendation letter might help. On the other hand, if I were to write such a letter...
In my experience, most communities of high achieving people don't openly value intelligence. Generally they dismiss it and say that hard work and luck is what's really important. And they would laugh at you if you wrote your IQ score on your resume.

If someone said "Person X is very smart" and didn't write anything else, I would see it as a backhanded compliment. Like "X is smart, but he doesn't have the traits that are *actually* valuable in academia."

In fact, if I don't like a professor, and someone asks me what it's like to work with them, I usually say something like "this guy is brilliant." Which is true for pretty much every professor at a good university.