This document discusses several cognitive biases and social psychology concepts including first impressions, stereotypes, confirmation bias, halo effect, optimism bias, aggression, and balance theory. An explanation for each concept is provided based on a video about a girl who judges a boy based on his appearance and confirms her initial stereotypes about him, despite her friend's advice. She insults another boy who trips and later wants to physically fight them. Her attitude changes when she learns the well-dressed boy she likes owns a car she dislikes.