Being ‘nice’ can hurt your career

TL/DR: "It’s important to point out the difference between kindness and niceness. Kindness grows from self-esteem and earns respect in return. Niceness comes from a desire for approval, which can result in mistreatment or being taken advantage of.

It really doesn’t matter whether your coworkers like you. It matters that they respect you and that you have a good working relationship with them."