Sibling rivalry

Here is a conversation that took place in my house -
Mark - Sam, I am named after one of the Gospels and you are named after one too
Sam - I have 2 books in the Bible named after me. You just have one.
My competitive 6yr old responds - My name is John. I have 4 books named after me. My name's not really Mark you know.

I often think about competition and how healthy it is. I've seen and experienced comparisons by parents and have heard so much of "If your brother can do this, why can't you" or "Look at her, she's so well behaved", "Do you have to laugh so loudly, learn some poise form your sister". There were things in which I had the upper hand so of course they got this too. But as I grew, I realized I resented the comparisons.

I've seen a lot of siblings fall apart because of these constant naggings. I don't think the comments need to be external. Unhealthy competition between friends have the same fall out. The resentment and the jealousy just keeps growing.

So is all competition unhealthy. I'd answer with the teenage chant of "No way!". Sports, academics and a healthy attitude of I need to be better than X can help us better ourselves and also is the motivation to get ahead. I don't think the world would have seen all the cool inventions that have changed our lives if it weren't for someone competing to do better. The important thing is that we don't lose our self esteem or stop loving the simple things in life to get ahead.
  
"The pressure people put on themselves and the rivalry between the teams is much more marked. And I think that's a good thing. As long as that rivalry remains within the spirit of competition, it con only spur everyone on."Eric Cantona