Both can be power-law or Gaussian depending on your “perspective”.
There are roughly as many people with a IQ over 190 as there are people with an income over 1 billion USD per annum. By roughly I mean an order of magnitude.
Generally IQ is graphed as a Gaussian distribution because of the way it’s measured—the middle of the distribution is defined as 100. Income is raw numbers.
(edited to move a scare quote)
Intelligence is but one measure of mental ability. One of the critical ones for modern life goes by “Executive Function” http://en.wikipedia.org/wiki/Executive_functions it seems to be moderately independent of IQ. It could also be called “Self Discipline”.
It is why really bright kids get lousy grades. Why kids who do well in High School, but never seem to study, tank when they hit college, or when the get out of college and actually have to show up for work clean, neat and on time.
I don’t CARE if you can solve a rubics cube in 38 seconds, I need those TPS reports NOW.