Newton's 3rd law: To every action force, there will always be an equal and opposite reaction force acting on the other body. Hmm, basically, this means that whatever you give, you'll recieve the same amount. However, come to think about it, is this really the case in real life? I beg to differ. Normally, the most common case is that people receive but do not give. That is to say that there will be one poor, lonely soul giving out to 5 other 'leeches', resulting in social unbalance.