People have different mindsets regarding the importance of competition and cooperating among children in order to nurture them as good members of society. I believe both of them are necessary for growing children.
When young people vie with each other in miscellaneous fields, it has some good and bad consequences. Firstly, their personalities become more aggressive or belligerent in some facets. Although this can help them to control their feelings better and muster boldness in some cases, they may be a little heartless and act brutally in society. Secondly, coping with different rivals resembles the real-life for children which is a must for them. Lastly, competing teaches children the real rules of victory and gaining power which they certainly need to know for their future professions.
However, the cooperating has some implications. Firstly, it helps children mastering leadership and management skills. Rarely have we seen inspiring leaders with a childhood lacking cooperative experiences. Secondly, cooperation awakens sense of altruism and motivates philanthropy activities. Lastly, cooperation may culminate in growing people with lenient or permissive characters that cannot provide formidable value for the society.
All in all, encouraging children to compete, or cooperate has different results in the process of growing a good member of society.