Generally, people’s behavior is the consequence of exogenous reasons and endogenous ones. That means a person behavior is result from the function of this person himself and the circumstance. So the statement, people’s is largely determined by forces not of their own making, is not a sufficient supported one.   Circumstance does have function on people’s behavior. The factors may be other people or other non-subjective ones. Probably, human might have explosive reaction from those factors near him. For example, when in the teenage, people will be involved with other members in the family, like parents. Parents are the first teacher of young. After they give birth to them, children even infant are good at imitate their behavior. In the beginning, is learning to eat. The parents firstly open their mouth and the infant follow it. Then the parent convey the food into their own mouth, and the infant follow it too. In this way, the infant learn how to grab the tools like spoon and forks by mimic the behavior of their parents.   When the infant grow up to an primary students, both family and school teachers will formulate its behavior in the public places. In a family, when meet someone they knew, the parents will demonstrate how to say hello to them to express affinity. After parents say, the children will be asked to regenerate a greeting to others. In another conditions, the children may rush around and making noise. When this happen, the parents will give a advise or a warn to them, that rushing in a house is unsafe and when inside a building, people should keep quiet.   Then when the children are sent to primary school, the duty of teacher may sometimes substitute the one of their parents. In a primary school, the teacher will teach the children some most basic usage of knowledge, such as listening , speaking, reading and writing. From the letters to words, from numbers to equations, the teacher teach child for their need and the basic element knowledge of communication and calculations. However, when a children misbehave ina public places, the teacher will correct it and inform them the reason, this is the same as family. And children will automatically mimic their peers. Starting to communication and make effect on each other.   Although family and schools are places which can correctly shape their behavior, there are many factors inside people’s mind that affect their behavior, too. When the teenage grow up, they will have their own hobbits and mind, they will learn to consider from different angles. I conclude these factors to be an endogenous one. For example, making choice for themselves is a typical process that endogenous factors determinate people behavior. When people feel happy, more positive behavior will exist, like smiling to others and be nice to them. However, when they fill annoyed, they will yelling at somebody, to express their anger and discontent. Sometimes, people behave according to their own preference, such as play football or badminton, go shopping or go hiking. These behavior are only decided by their own choice and demand.   In conclusion, the factors to what decides human’s behavior is not a statis one. People can make choice for themselves or involved with other factors which are objective.