I live in Northern Ireland, and we have many different groups of people that all listen to different / mixed types of songs. I have observed for quite some time now (Years) that certain people that listen to certain music behave in certain ways. The biggest impact music has had in Northern Ireland has been the annoying repetitive dance/rave music. What effects music has on the brain I do not know. I consulted Microsoft's Encarta 2005 for some info on this, but it didn't have anything on music’s effects on the brain. I'm not sure about where you live and what cultures of music you have there. But here is just a little chart / information table I have compiled from a series of silent tests I have secretly performed on people without knowing them / them realizing I’m testing them. For the record; I am a fan of Rap, Rock and Metal. Dance/Techno/Rave - Generally listened by those in adolescent years - Majority of those who listen to this music, have appeared to be 'Slow idiotic and mostly incompetent. Constantly in a state of anger, always vandalize public property or physically injure others for no reason. Always abuse drugs and alcohol. Mainly the British, but allot of the world know these types of people as Chavs (see www.chavscum.co.uk) Rap - Generally listened by those in adolescent years - The minority of those who listen to this music turn into standardised Eminem’s and use drugs. Not always idiotic, incompetent, but about 60% of those who only listen to rap are ill-mannered. Rock - Generally listened by those in adolescent years and the middle aged generation - The majority that listen to Rock music, are well mannered, polite, hard working people, and usually quite intelligent. Metal - Generally listened by those in adolescent years - Quite a mixed genre of music. Majority are well mannered, polite, hard working, intelligent people. But those who are not are, Maniacally depressed, constantly angry, enjoy grotesque things such as dead bodies / animals. Classical - Not very widely listened to. Despised by the Rave culture, Rap culture, liked by the rock and metal culture. I have selected these genre's of music, as they are the most prominent in NI. I have a theory for the reasoning behind music behaviour. When listening to music, your brain releases more testosterone or Forgot the name of the female equivalent to testosterone (Let's call Testosterone etc 'X') which in turn, makes you more hyper. The faster the music beats or more "active" it is, the more X your brain releases, causing you to do things you wouldn't normally do unless perhaps under the influence of drugs or alcohol. What are your views on this subject?