Answered on Quora.
I have a 147 IQ, and I have met three people with higher IQ’s: a therapist with a 160 IQ, and two women, both with 156 IQ’s.
Although the therapist is almost a full SD above me, I could not tell much difference between us, and it certainly did not seem like he was smarter than I was. In fact, I knew some things he had never heard of, and I had to explain them to him. He was wicked smart though. I would say we were equals.
The two women – one with a 156 IQ I talked to for three hours one night. I did not think she was smarter than I was, but she was damn smart all right.
The other woman is an Austrian woman with a 156 IQ. That is over 1/2 SD above me. She was literally one of the fastest people I have ever met in my life. She was blazingly fast – as fast as lightning. You don’t often meet someone that fast.
Also, in the course of talking to her, I mentioned a few concepts she had never heard of. They were not simple concepts either. She would ask, “What’s XYZ Concept?” I started to explain these relatively complex notions to her, and she got them very fast, with a minimum of explanation. Most people don’t pick up entirely new concepts so fast like that.
She was one of the most impressive human beings I have ever met. She was also a very good person, I might add. On the other hand, I didn’t really feel like she was smarter than I was, despite her blazing speed.
So, 147–160, I see no differences.
Actually, all the way down to 125 IQ, I typically do not see much difference between them and me. A 125 IQ is a full 22 points below mine – 1.5 SD’s (!). People with IQ’s around that range seem to be about as smart as I am. Anyone from 125–140 IQ seems about as smart as I am.
So, taking them all together, I do not see a lot of differences between 125–160 IQ, and I am right in the middle of the range. Keep in mind that that is a full 35 point IQ gap – almost 2.5 SD’s!
My theory is that at the high end, the IQ’s all wash out, and there is not much observable difference between them. You have a lot of very smart people, and it’s hard to figure out who’s smarter than anyone else.
The differences are much more prominent at the low end.
Compare 1.5 SD difference for me – 147 IQ versus 125 IQ, a 22 point difference which almost seems invisible.
Now compare at the low end. 1.5 SD difference – 100 IQ versus 78 IQ. I can guarantee you that there is vastly more difference between the 100–78 pair than between the 147–125 pair. The differences among the 100–78 pair will be breathtaking.
