Group learning vs one on one learning-which makes kids more active and why?

I think both have their pros and cons. In one-on-one learning, the kid can fully concentrate on what he is doing without getting distracted much. The kid can get personal attention. But at the same time, these things itself can irritate him and can make learning monotonous for him. Whereas, in group learning, kids pick up things seeing each other. If say, they don't understand what the instructor is saying, he picks it up from fellow students. Kids become competitive in group learning. They become interactive, spontaneous and develop sportsmanship as well. And it can also be that kid is unable to focus on things because of so many kids around. If someone is introvert then he can also get more into his shell if he is unable to compete with others. So, I think, both ways of learning have their positive and negative aspects and in my opinion, one should not be solely exposed to one form, and should be given switch to maintain the equilibrium.