The thing is it’s likely an evolutionary adaptation of being overturned for… something. I suspect hunting. Hearing a twig crack, being hyper focused and not being able to get something out of your head. Tracking your prey for hours, these would be useful in a low stimulation environment like say, the woods of Europe 20,000 years ago. It’s certainly a deficiency in most modern humans as we aren’t out chasing down prey, but that doesn’t mean it was never a useful trait.
reply> It’s certainly a deficiency in most modern humans as we aren’t out chasing down prey, but that doesn’t mean it was never a useful trait.
replyBalance. The inability to "focus" attention at the likely relevant thing as a matter of course is suboptimal. You don't want to get distracted by the wrong thing when it is a matter of life and death.
I don't know that your theory is any more likely than a theory of ADHD being less likely in those before-times because it would get you killed because you're not paying attention to the right stuff and nature then stomps on you. Not that I have any reason to believe this idea.