Is competition healthy?

When you were a kid, did your parents ever compare you to your cousin, your sibling (if you are a twin), the next door neighbour, if you were of similiar age and sex? My mum used to always say that so and so (a relative in London) was bigger than me (in height) even though I was older, and she used to compare me to some other girl that used to visit my aunties chippy (who looked scary) and it used to DO MY HEAD IN!!!

My son has a cousin who is 6 months younger than him, and his cousin is taller than him and can probably read better than him and they both started mosque (learning to read arabic) and even though my son started 3 months before him, his cousin has now caught up with him!

So, is competition (and comparing him to someone else's son) healthy? Is it a good thing? Well it works both ways. I remember the only reason I started potty training my son was cos his cousin's mother was about to start him and I really couldnt have her son out of nappies before mine could I? So in some ways it is good, but i have to stop (mentally) comparing them as they are essentially opposites. They have different personalities and the main thing they have in common is their age. I know that my son is better at other things than his cousin so i really shouldnt feel bad if his cousin excels him in some areas. I need to make a mental note to stop being so petty!

Incidentally the only reason his cousin caught up with him was because his teacher started comparing them and she deliberately put his cousin up to speed so he could catch up with my son, calling it a "competition", now that's what I didn't like cos its not good for them to be in competition with each other as one will inevitably will be made to feel bad by an adult (in this case the teacher).