placebo effect

This scenario showcases a placebo effect as the kids believe they'll do better with the "luck from their attire". There really isn't any source of luck on whats being worn. Its really the mind set and confidence which helps them perform well in their tests. Just having that sense of extra confidence that there is some sort of luck had a positive response, just like the placebo pills. Both of the kids believed that their socks had some sort of luck, one performed well, while the other child did not perform well due to the thought of not wearing the "lucky socks".