So, some people seem to come on social media, and instead of responding to others' posts or comments, they divert from the topic and exhibit what they know although nobody is asking for their knowledge. They also often come on sounding arrogant and condescending like "You don't know what you're talking about, so I shall educate you."
So, why do they need to behave like that? Do they want recognition and admiration by exhibiting their knowledge because they are lonely and nobody pays attention to them in real life? Do they want confirmation or reassurance because the truth is that they lack confidence in real life? Or are they simply narcissistic and self-indulgent? What kind of psychology do you think it is?
I like to think that most of these sorts of people have never been taught, or they are incapable of critiquing their own thoughts and those of others. They go around thinking out loud a lot, looking for a really good argument but usually based on their terms. Many will acquiesce to a superior argument, what Peterson is famous for, the rest are what I think you well described and are found hang around at the edges of society.