Where are you getting this from exactly ? Getting in to a medical school is very difficult to do in the U.S. Having an average IQ of 105 would make it borderline impossible - even if you cram for SAT and tests twice as much as everyone else there is so much you can do - these tests test for speed and raw brain power. In my country - the SAT equivalent you need to have to get in would put you higher than top 2%, it's more like 1.5%-to 1%, because the population keeps growing but the number of working doctors remains quite constant. So really each high school had only 2-3 kids that would get in per class. I know a few of these people - really brilliant kids, their IQ's were probably above 130 and it's impossible for me to compete with them in getting in - I am simply not exceptional - at least not that far high in the distribution. I was maybe in the top 3-5 best students in my class but never the best, so lets say top 10%, these kids were the best students in the whole school - that's top 1%-2%.

One caveat to all this is that sure, in some countries it is easier to get in. People from my country (usually from families who can afford it) go to places like Romania, Czechoslovakia, Italy etc where it is much much easier to get in to med school (but costs quite a lot and also means you have to leave your home country for 7 years).

Now is it necessary to have an IQ off the charts to be a good doctor - no, probably not, but that's not what I was arguing, that's just how admission works.