A dozen or so years ago I ran across the old military classification of Smart vs. Stupid and Lazy vs. Active.
The top posts were to go to Smart & Lazy, because they figured out the most efficient ways to do things. Never to be allowed in the military were Stupid & Active, because they got everyone killed.
The bulk of soldiers were Stupid & Lazy, because they did the bare minimum to get by but didn't cause any trouble. Smart & Active made good officers, but again, the top promotions went to Smart & Lazy.
I found that simple classification to be very accurate on judging people.
There are more advanced tests, such as the MBTI and the Enneagram, but they are more for self-knowledge and in order to use them to understand someone else, they have to take the test and you have to know the results. That is a problem.
However, what I found to be more accurate is to refine Smart/Lazy/Stupid/Active to Smart & Stupid and Introverted & Extroverted.
The dumbest people in the world are the Stupid & Extroverted. They are the ones who fill the prisons and commit almost all crime. They are impulsive, i.e,. they act before they think. That's one of the big reasons they get into such trouble. They're too stupid to see cause and effect in their own lives. They're the kind of people who can't even learn from their own mistakes.
Next up are the Smart & Extroverted. Remember I mentioned they were never to be given the top positions? There is a good reason for that. They can't handle them.
Many politicians are Smart & Extroverted, and they are the ones who are always trying to do Good Things ("The road to Hell is paved with good intentions"). They start wars and screw up the economy. They're why democracy doesn't work and always fails. By the way, some politicians are Stupid & Extroverted, such as one who thought islands could tip over and another who thought when "assault weapons" were out of bullets they couldn't be fired anymore - ever.
The we have Stupid and Introverted. They're the ones who do just enough to get by. I've never seen much of a problem with them. I don't think anybody really has.
I am the Smart & Introverted, and we are, again, the ones who should rule. Mostly because we don't want to, and power has no allure for us.
There will always be problems between the Extroverted and Introverted. The smarter Introverts understand the Extroverts a lot better than Extroverts understand the Introverts. No Extrovert is ever going to understand an intelligent, imaginative Introvert wandering in the evening figuring things out (and getting so absorbed they fall into ditches, as the famous Scottish economist Adam Smith did).
A good movie about the conflict between Introverts and Extroverts is The Eternal Sunshine of the Spotless Mind. Jim Carrey plays an Introvert (although his schizoid portrayal is more what people think an introvert is, rather than what they really are) and Kate Winslet plays a ditzy scattered Extrovert. They ultimately don't get along, because they don't know what they are. The words Introvert and Extrovert are never used in the movie. If they knew what they were they would have gotten along a lot better.
You can also see the difference between Smart Introverts and Stupid Extroverts in the movie, Idiocracy.
As for the conflicts between men and women, there are far more smart men than women (there are twice as many men with IQs above 120 than women). There are far more many extroverted women than men.
The inevitable conclusion? There are an awful of Stupid Extroverted women out there! That's what causes a lot of the problems are between men and women. (I've heard these Stupid Extroverted women referred to as Manic Pixie Dream Girls.)
Since these women often turn into catastrophes in their personal lives, they have to be ruled by men, because when they gain any kind of power they get busy trying to improve things but instead screw them up. They're not smart enough to realize what they are doing and instead rationalize it.
I have found most of the complaints against women in the Manosphere are against Stupid Extroverted Women. Unfortunately, many of the men don't know what the problem is. They think all women are like that, which is why they come up with inaccurate concepts such as "rationalization hamsters." Which, again, applies to Stupid Extroverted Women. Not Smart Introverted Ones.