Science reveals that irrational, inexplicable teenage mood swings aren't only normal, they're helpful and beneficial - even if they are painful for parents and teens alike. Teenagers may be sulky and surly one moment, exuberant and ecstatic the next. And it's more than hormones that brings on these extreme teen mood swings, it's their developing brains that are also to blame. Teens are at a cerebral crossroads; their brains driving new ways of thinking and feeling, and how teens learn to manage their moods can either empower or derail them for the rest of their lives. The Teens: In this episode we meet four young Australians each with their own story to tell about the emotional roller coaster of being a teen. The science behind teen moods is told through each personal experience. Aaron, Estelle, Sarah and Rebecca are all experiencing life as a teen in different ways and talk about their moods and situations. The independence seeker, the popular kid, the misfit and the depressive all face their own challenges of mood as they negotiate their way through the teenage years. The Science: The latest science shows that typical teen moods have very little to do with the effects of pubertal hormones. Scientists have recently found that the teen brain is itself in conflict, caught between heightened sensitivity to emotions, while at the same time lacking the skills to control feelings. At the same time teenagers' brains are going through this transformation, teens are thrust into a volatile and unstable social world. It's a perfect storm for emotional upheaval, negativity and just plain teen angst, but it's also an essential part of becoming an adult.