And yet intelligence facilitates making better judgements on likely/possible consequences than not.
A doctor I used to know in Arizona told me whenever he had people in the ER for firearms accidents, they were usually college educated people there on vacation. The less educated locals were safer. I don't think intelligence has much to do with it. A five year old can be taught that if you point the gun in an unsafe direction and pull the trigger, someone's going to be hurt. They can understand the consequences. They just don't always judge risk real well. Same thing that people do when they're driving.
Any 2nd grader can tell you to stop on red, or that the speed limit is 70, and that it's dangerous to break the law. But a lot of adults with high IQs will still take that chance when they're late for work.