Okay, for all the explanations of the other silly questions, I honestly don’t think there’s any way to understand this one. The attorney already answered the question themself! Despite what this witness thinks, it’s relatively impossible to have an IQ of 20. The lowest score people get is generally 70-79.
That indicates that someone is cognitively impaired, and around 6.4% of Americans fall into this category. The most popular IQ is between 90-110 for 51.6% of the population, which, as you might expect, is average intelligence. The smallest number is the gifted population of above 130 IQ, which is 2.1% of the population.