There are two possibilities to categorize behavior: on one extreme there is the aggressive behavior and on the other the passive behavior. In the middle of the two poles, you find the assertive behavior, in which you express your desires and claim your right without disadvantaging the other part.
Work environments where aggressiveness is rewarded work after the same set of rules like in the jungle world. Between animals, the alpha position is obtained after a fight. A successful fight means there to obtain the position of the leader, so aggression is in the animal world obligatory to assure the protection of the species. Alpha Males protect and lead their followers, so they have a privileged position.
Compared to the animal world in human societies aggression is associated with domination and this behavior can be often found in jobs with a higher competition like leadership positions.
What does aggressiveness at work mean?
Aggressive behavior hides fury. Aggression shows that furious energy is transposed into action to win a fight. It is also possible that there is a feeling of competition towards the other person, whom you perceive as a threat. Or it can manifest the intention to eliminate the others in order to find your peace. So if your colleague is aggressive it might be that he fears that you can take his or her position, because you are more competitive. Aggressiveness is used as a form of intimidation.
Other causes can be connected to unrealistic expectations at the workplace, work pressure or crisis situations. In this case, aggressiveness represents defensive behavior caused by feelings of fear and insecurity.
In the relationships with clients, aggressiveness can manifest, when those have uncooperative solicitations or attitudes, they can represent a threat or danger.
How to be competitive and performant without being aggressive?
Competition at work is linked to our intrinsic motivation, that means our motivations should stay in connection with our own person and not the other people around us. The competition with your own person stays in the continuous improvement of your own skills and learning new competencies to reach your goal. In this way, you do not come into conflict with other persons. Finally, also your self-esteem will grow.