Replying to Skiing with other people

Alright a friend and I were haveing a debate about wheather or not skiing with other people will make you ski better. I said that other people can puch you more then you can puch youself, he said thats only true for some people but other puch themselfs. I would agree that some people can puch themselves but i think that they progress more with others puching them. What are your oppinuns, do you progress more with others or by yourself