I do think guns make people stupider.
Well, yeah, sort of. Robert Heinlein had a quote (which googling would not find for me) to the effect of "The most dangerous gun for you is the one you're carrying, because it will give you false courage and you'll stay in a situation where you should have left."
But do check out the rest of the story:
[Her ex-husband Gerry Katz] argues that her desire to take her gun to school is about reopening their divorce to get exclusive custody of their 6-year-old daughter.
"She's just scamming everybody," he said. "As soon as this thing started ... I called the principal at her high school and told her ... I am not coming to your school. I am not a threat to her. I have no desire to hurt her."
Divorce is a worse risk-factor for stupidity than guns are.