You’re definitely right about that I freely admit I’m not an expert in this field yet but I am an SLP and completing my PhD being trained by some experts who do this research clinically and neurologically. The quoted paper in 1967 had been disproven and rejected by the academic and clinical community a long time ago. I read the self published paper they posted and there are so many flaws in the reasoning and explanations for it. You can’t base a theory on a faulty premise. Also, as a stutterer, we have spent too much time and effort moving away from saying that stuttering is learned and it’s within our control because that implies it’s our fault and choice to stutter. That is so incredibly harmful and still believed in a lot of places. That’s the exact thing I was told growing up that I need to calm down and just stop doing it because I wasn’t smart/skilled/intelligent enough to speak correctly. It’s harmful and damaging and I am heartbroken for anyone else who thinks and believes that still.