This study seems like common sense. Extroverted people who are agreeable climb the fastest.
People confuse disagreeable with “asshole”. Most assholes can be agreeable, just how they play the game is disagreeable. Political assholes take credit for others work and never take risk. Controlling assholes micromanage and suggest everything was their idea. Most disagreeable people hardly get promoted. It seems rather obvious that being liked tends to serve you well regardless of your expertise. Of course the Peter principle and Dilbert principle can kick in because of this.