People value intelligence and will apply that label to themselves even if it may not be true. It's a hard thing to measure though IQ does it reasonably well. To those who have a high IQ: what is it like? Can you pick up any book, read it, and understand the gist with minimal repetition? Can you infer solid and accurate conclusions based on a small amount of evidence? Is any subject or discipline up for grabs or do you have to have a keen interest in a particular field in order to flourish? What is something you are able to do that you know is because of your intelligence -- the proverbial 1,000 pound deadlift of the brain, if you will.
There is no point to these questions other than curiosity.
That's all and good, but let's go back to the original claim that was being discussed.
If you define "basic interaction" as anything short of discussing economic concepts. Sure, it's impossible. But, to me at least, "basic interaction" means something you can manage with someone who barely even speaks your language.
Not being able to communicate with some 2 SD less intelligent would mean that someone with 129 IQ could manage better than basic interaction with someone with 100 IQ, but someone with 131 IQ would not be able to. Obviously a flawed premise. The decisive factor in the complexity of communication is the minimum of the two IQs, not the delta.