There is no "I" in team – a pretty well-worn statement, but very true in practice. There are many teams that have assembled great talent, experience and skills only to fail in their objective because of a lack of teamwork.
Invariably this occurs where people put self before team – in fact, the more you read on teamwork (success and failure) the more you see that people are hard-wired to put self ahead of the team – even when the success of the team will ultimately deliver greater reward.
In the sporting sense this is often seen where a star player will take the shot rather than pass the ball or will ignore an instruction by the coach and do his or her own thing, the long-term outcome being a lack of success in terms of the results being strived for.
Bluntly, in my view, if you are part of a team and you have a selfish teammate you are doomed to failure or, at best, you will get significantly lower return on your efforts or you will need to work twice as hard.
