TL;DR: men can get away with and benefit from being less agreeable. Women who are not agreeable get screwed over.
The reductionist approach is science is powerful. The idea is that, to the extent possible, we hold all variables constant except one and look at changes in outcome from a single variable. Using statistical tricks, we can often isolate a single variable (for example, a personality trait) in an uncontrolled population. This can tell us a lot about how the world works, but it can deceive the unwary.
It is a category mistake to base your life on this because your life is not governed by one variable.
For example, suppose you asked “Does using cocaine make you happy?” Real world, uncontrolled data won’t help you because people who use cocaine can have health problems, legal problems and get fired from their jobs for it. So, a scientist studying this will compare cocaine users to others who have similar legal, health and occupation problems from non-cocaine causes and compare cocaine users who have no no problems from it to similar non-cocaine users.
Suppose this study found “cocaine makes people happier.” It is possible, but not an endorsement of cocaine use. It is possible that cocaine users are less happy because they have other problems with higher frequency than non-users.
The “Big Five” personality traits are a staple of social science. They are Openness to Experience, Agreeableness, Conscientiousness, Extraversion and Neuroticism. It is unclear how good this model is, but it is definitely better grounded than Meyer-Briggs. Unlike M-B, this model actually has predictive value. One area where it has predictive value is income.
In 2012, a study reproduced what was already well known: people who scored in the mid range on the agreeableness factor earned more income over their lifetimes than those who scored low or scored high. The study cited all kinds of references attesting to this that you can read about in the introduction f you can access the real paper. But they produced a press-friendly summary here:
Numerous press outlets reported that nice people earned less money. The title of the paper was “The Joint Effects of Sex and Agreeableness on Income” but many press outlets left out the “sex” part. In the above examples, the NPR story didn’t get into the sex effects until halfway through the interview. By 2018, ABC news had forgotten about the massive effect of sex and gave advice aimed exclusively at men without mentioning that this affects women differently. The Workopolis story noted the effect for women was smaller but implied (wrongfully) that being agreeable was a good career strategy for women.
Agreeableness had 2 distinct effects on income: one, agreeable people were less likely to be fired than less agreeable people. This caused less disruption to their income allowing them to earn more. Two, less agreeable people were more likely to get promotions and pay raises. On balance, for people overall, less agreeable people earned more.
There was a powerful interaction between sex and both of these effects. The benefits of the increased promotion and pay raises was six times greater for men
than women. Furthermore, women were more likely to be fired for being non-agreeable than men were. The net effect was women who were agreeable earned more than women who were less agreeable, while men who were less agreeable earned far more than men who were more agreeable.
Oh, and men, on average, earned more than women regardless of agreeableness v disagreeableness.