If you are interested in psychology, go and study it. Sure, it's just a scratch. Don't expect to understand other people's psychology. It's useless.
Writing is just some knowledge of language writing from primary school to junior high school to senior high school, which is useless.
The most useful is general logic. If you are smart or you want to be smart yourself, learn this. During our four years in college, everyone said that the only useful lesson was this logic. It's a pity that the teacher didn't finish teaching the contents in the textbook. Learning it, speaking and discussing opinions will improve N levels, not only at work, but also in daily chat. Think about how great it is to say "your words are illogical" and "there is no necessary connection between your reasons and your conclusions" ... it will make others speechless.
If you are lazy, study first. If you are an enterprising person, you must challenge logic. Strongly recommend