I think you are right, and OP fell victim to the Availability heuristic.
4 SD above average is 160 IQ, which is a normal level of “very smart.” Everyone reading this probably personally knows someone around that level. And we can almost see the impact a star programmer, or an Einstein, makes on the world.
4 SD below average is a) not well measured because “nobody” cares once you go below 70 (2 SD); b) not going to be making an impact on society; and c) not going to present too differently than an IQ 70 person—you don’t know if it took the person stocking shelves 1 hour, 1 day, or 1 year of instruction to reach maximum shelf-stocking skill.
I think you are right, and OP fell victim to the Availability heuristic. 4 SD above average is 160 IQ, which is a normal level of “very smart.” Everyone reading this probably personally knows someone around that level. And we can almost see the impact a star programmer, or an Einstein, makes on the world.
4 SD below average is a) not well measured because “nobody” cares once you go below 70 (2 SD); b) not going to be making an impact on society; and c) not going to present too differently than an IQ 70 person—you don’t know if it took the person stocking shelves 1 hour, 1 day, or 1 year of instruction to reach maximum shelf-stocking skill.