science is not based on common sense and in fact, oftentimes human "common sense" is actually wrong. It may not seem like an important study to some but the study of the relation between video game playing and learning/development is a very relevant topic as there is so much accessibility to such game consoles now days. The relation is there and now developmental theorists can discuss just why this exists there were several good examples given in people's posts here). And thus those ideas can then be tested in more specifically designed experiments. And this ladies and gentlemen is how science works.