Your account’s been active here for 2 months and from what I can tell aside from this you seem really cool so I’m happy to have a good faith discussion about this.

The heat/better governments stuff is what historians call Environmental Determinism. Even in the liberal dominated field of academic history, Environmental Determinism is widely regarded as fashy crank shit to the extent that showing someone’s theory/paper is or relies heavily on environmental determinism is usually enough to refute it. Clearly the environment is a factor in the way history has played out and a whole field called Environmental History has developed to study the interplay of how humans and environment have affected each other throughout history, but to imply that it’s the primary or only factor is insulting, super racist, and almost always untrue. If you google the term “Environmental Determinism” you’ll find a lot more numerous and eloquent critiques of the idea than I can write here in a reasonable amount of time.

For a specific refutation of people who live in hotter climates being more violent I’d look to the entire continent of Australia. The indigenous people of Australia developed one of the single most peaceful and stable cultures we’ve ever known, while living on a continent where temperatures push 40 degrees Celsius (104 Fahrenheit) almost continent wide pretty much every summer. The google scholar you linked shows a lot of papers linking crime waves with heat waves and increases in violence when it’s hotter than usual in an area, but nothing to say regions with hotter climates are more violent than areas with colder climates. This would seem to imply that people are more prone to antisocial behaviour when they’re hotter than they’re used to, which also makes intuitive sense. If anything this would support the opposite of your theory, as in a global world where air conditioning exists people adapted to hotter climates are less likely to feel uncomfortably hot 😜.

On the Vietnam/Cuba thing I’ll admit I’ve never been to either and I also have strong anarchist sympathies, I think most communists should given our ultimate goal is, you know a classless stateless society, but I think condeming them too harshly is making the perfect the enemy of the good. Modern communist states like Vietnam or Cuba are far from perfect, but they’re usually far better for their people and the rest of the world than non-communist states and anything saying otherwise is almost always either written, funded, or heavily cites texts by an organisation that has done far worse things than them and has an awful and very clear reason to make people try and hate those states.