When I ate a high-carb diet I was stressed and anxious. Meds, meditation, exercise, yoga, supplements, herbs, standard so-called "healthy" foods, etc. didn't help much. I tried everything that people recommended. Then when I ate Paleo the stress melted away--I could literally feel my muscles relaxing and releasing tension and even got feelings of euphoric well being. Unfortunately I gradually increased my carb consumption and some of the stress and anxiety returned, though not as bad as before. Then as I moved to ZC with lots of healthy animal and fish fats the increased calm and euphoria returned. Now people remark about how calm and composed I nearly always am, and I notice the frenetic, fast-talking, negativity of the carb eaters buzzing around more than ever. Sometimes I take a glance at what the most frenetic people are eating or putting in their shopping carts and it is invariably mostly high-carb foods.
One of my sisters eats tons of carbs and she can't stop talking endlessly at lightning-speed. Her fast-talking has worsened over the years while I have become calmer and calmer, so it's apparently less genetics than diet. I joke and say she does the talking so I don't have to.
I'm embarrassed to admit that in my high-carb days there were times when I would rapidly cluck along too. That is increasingly rare these days.
I do other stuff to relax too, including much of the above, but none of it has had nearly the effect of ZC RPD, so I won't bother to post it.
I've read some accounts about first-contact Native Americans and other traditional peoples who remarked that the "white men" talk too much.
I've even noticed that from the videos of various hunter-gatherer groups I've seen, that the higher-carb dieters like the !Kung San seem to cluck-cluck more than the big-game hunters like the traditional Lakota and Inuit. The only fast-talking Lakota I've seen were big-time carb eaters who loved fry bread and the like--and one even extolled the virtues of fry bread. Little did he know, he displayed other examples of diseases of civilization from his love of fry bread: myopia, lack of much muscle fiber, malocclusion, teeth crowding and thinning hair.
You can learn much about many different things by studying traditional hunter-gatherers and emulating them and also studying high-carb dieters and avoiding doing what they do.