Science - Growth hormones are a natural substance created by your body just like testosterone. Human growth hormones however are genetically made hormones that help you get bigger. They were invented to help people who had developmental problems and could not grow to their appropriate size. This synthetic mixture was only available to people who absolutely needed it but began to be sold other places and people began to get their hands on it. The HGH itself does not get a person big, but depending on their daily activities may result in size difference. It is not a steroid, but considered a "doping" substance.
Society - HGH is not commonly known, and is often taken by bodybuilders and athletes even though it is banned in some organizations. These growth hormones when taken properly are very beneficial to your body. Athlete have been known to tear ligaments and take HGH's to speed up recovery time. The hormones are looked at as giving unfair advantages to athletes so it is frowned upon. It works by boosting testosterone levels in effect making a person work harder, lift more, and get better work results. Though it does not make them better, it is a Performance Enhancer.
Self - I have never taken a growth hormone substance, but I think it is cool how our bodies react to different substances and the length people will go to just to achieve big muscles.