Part 1 of Essay
is a sleep disorder effecting an estimated ten percent of all humans at least once in their lives. This widespread phenomenon varies in its intensity and frequency. While most incidents are short and not dangerous, some can involve self-injury and are much more dangerous for the sleeper as well as the people around them. ....

Part 2 of Essay
.... grow out of, while with older people, stress and substance abuse play a larger role. is most common among children from the ages of 4 to 12. Estimates for the percentage of the population which will sleepwalk at least once in their lifetime range quite a bit. Some sources say that most children will walk in their sleep at least once, with 15% of them more regularly. Others claim that 18% of the population is "prone to ". There is consensus, however, on the fact that boys sleepwalk more frequently than girls ....