Anti-social means not knowing how to be appropriate socially, while asocial means avoidance of social life. Anti-social behavior is caused by harbored anger and resentment towards either society or some trauma that has occurred. It is also perpetuated by negative thinking, as asocial behavior develops and can become a fixed attitude concerning life.
It could be cultivated because of an introverted nature, autism, and schizophrenia. Anti-social behavior has the propensity to harm society. These people are not capable of feeling guilt, even though their actions offend others. They do not have a perception of right and wrong.
Asocial behavior is seen in those who have poor self-esteem, and they are anxious in new groups of people, and they fear rejection. They will often avoid trying to have a social life because they are afraid of rejection.