This is the normal reaction of many participants during our session to improve Team Collaboration. Most of them are shocked that this is one of the hidden beliefs that acts as a blockage in their career success.
But it's not all that surprising. If we analyse that why don't teams collaborate than many issue may surface but one surprising fact is lack of self-belief in team members. Coming to think of it, is it so surprising.
Why do brothers have property disputes. Among many other issues isn't it the belief that "I'll never be able to create this much property on my own, so why should I allow my brother more than his share", and isn't this a lack of self belief.

Similarly in organisations the hidden belief one has is that, "I am not good enough, If I help somebody then that person will rise in his/her career, but what if nobody helps me and I am not good enough to rise on my own, so why should I help somebody. In fact I should try to pull others down" and so on.
Making the participants aware of such toxic and hidden beliefs is the foremost important step in helping them unlearn such blockages and achieve their potential. However it's not an easy task as it's a very delicate issue. Thankfully Mind-Programming is a powerful tool to make participants discover their blockages themselves and inculcate a strong desire to unlearn them..