A thought experiment: There are two borderless rooms that are the same. They contain identical people (the first room contains people with the same appearance, personality and character as the second room). In these rooms the life of an average person is simulated and two different newborn children are put in these rooms and they live there all their lives. All the activities that the people in room 1 will do are repeated at the same time by the people in room 2. Around the age of 60 of these children, their character and personality will be compared. If they have the same character and personality, this will mean that the character and personality of the person is formed by the environment of the person (people, location, friends, etc.). If they have different personality, the same experiment will have to be done but the newborn children will be 100% genetically alike. If in this case, the children will have the same character and personality, it means that the character and personality is formed due to human genetics, and if they have different character and personality, then the formation of the character and personality is influenced by something else unknown to science. Since it is impossible to conduct such an experiment, it is impossible to know how personality and character are actually formed.