One aspect I always found interesting is that a teenager's prefrontal cortex is still developing. That area, in adults, is usually active in planning, judgement, and impulse control. http://seattletimes.nwsource.com/html/health/2002163863_healthteenmoods30.html

A teenager's brain is absolutely stuffed full of knowledge, particularly about life and life's experiences. Because of this they know absolutely everything about everything. Unfortunately, some time in their 20s this knowledge disappears overnight and they become just like the rest of us, realising how little they really do know.

Very interesting question. I have heard this before but have never really looked into it. While researching your question I found some information regarding the differences between adult and adolescent brain development. It seems there is a difference in terms of the region called the prefrontal cortex. It is the prefrontal cortex that tells us when to act on our anger, or curtail it, eat that second piece of dessert, or go without, seek immediate gratification or hold off for the long term, basically decision making and behavior. Teens handle stress and emotions differently as well. These differences between adolescents and adults have a basis in brain development. Throughout childhood, the brain undergoes dramatic changes. Nerve cells grow and they develop more connections. A substance called myelin covers the cells, increasing the speed of nerve signals about 100-fold. Finally, "pruning" occurs, which eliminates connections that are not needed. This makes communication more efficient from nerve to nerve, from circuit to circuit, and between the right and left sides of the brain. Nerve connections evolve throughout life, but the biggest changes occur from birth to the early 20s. Each brain region undergoes the growing and pruning process at different times. Basic functions (the ability to smell, see or move) mature first. The areas responsible for more advanced tasks mature later. For example, the part of the brain that controls vision (the visual cortex) starts its burst of growth when a baby is 4 months old. By preschool, it has been pruned to its adult level. In contrast, the reasoning part of the brain (the prefrontal cortex) starts its growth spurt at age 3 or 4, and most pruning doesn't occur until middle or late adolescence. Among the last connections to mature are those between the prefrontal cortex and the "emotional" part of the brain (limbic system). Emotional learning and self-regulation depend on these links. A circuit of particular interest is the one that links the reasoning parts of the brain to the brain's reward system. The weakness of this connection during adolescence may explain why teens are particularly prone to the power of addictive substances and romantic love. For example, adolescents become addicted to nicotine faster and at lower doses than adults do. And brain scans show that the brains of teenagers are much more sensitive to novel experiences compared to adult brains. Hormones are at work, too. The adolescent brain pours out stress hormones, sex hormones, and growth hormone, which in turn influence brain development. Testosterone production goes up 10-fold in adolescent boys. Sex hormones act in parts of the brain that are important for the regulation of arousal and mood. It seems teenagers really do need the advice and supervision of adults, even if they don't think so ;- } As a mother of four, this certainly explains a lot! I'm glad I saw your question ... and decided to look into it! Thanks! ; - D Here are some sites if you want to read them ... very informative. http://help4teachers.com/prefrontalcortex.htm http://www.pbs.org/wgbh/pages/frontline/shows/teenbrain/interviews/todd.html http://www.sciencedaily.com/releases/2004/10/041030131905.htm http://www.nimh.nih.gov/health/publications/teenage-brain-a-work-in-progress.shtml http://www.usatoday.com/news/health/2007-09-26-teen-freedom_N.htm http://72.14.209.104/search?q=cache%3AoyV_iqUpnogJ%3Ahttp%3A%2F%2Fwww.teenpregnancy.org%2Fresources%2Freading%2Fpdf%2FBRAIN.pdf%20adolescent%20and%20adult%20brains http://72.14.209.104/search?q=cache%3AqwUAnxwstAIJ%3Ahttp%3A%2F%2Fwww.actforyouth.net%2Fdocuments%2Fmay02factsheetadolbraindev.pdf%20adolescent%20and%20adult%20brains

Mostly the same. Maybe a crinkle or two less.