Self-preservation: that's exactly the reason why people tend to wear masks. Constantly, it is man's natural tendency to protect oneself and prevent any harm to happen. Harm can come to anybody and it takes numerous forms such as physical, emotional, psychological, and others.
Since birth, one is already surrounded by people who protect him from any harm. And one is told since younger stage to adulthood to prevent from harming other people. However as part of growing up, no one could avoid being harmed or hurt by external and internal matters. As a result, people tend to wear mask to prevent from being harm.
Try to ask oneself, "How many masks I wear in myself?, What kind of mask do I wear on this or that occasion?", and other questions. When one is just with himself, he tends to be the most natural in him and devoid of any reservation, he can show to himself his true self. However, as he goes with others like friends and buddies, then he also tends to present a different kind of personality.
And when he is facing another group of people like the elders, he also shows a different kind of persona. One can count of several kinds of masks that he is wearing on various situations as well. One of the prominent reasons of this is that he tends to preserve his self by doing so. Another reason is that the person is scared and apprehensive that if he will show the true self, others would not accept him.
Being accepted by others is one of man's primary needs so it is then very essential for anybody to feel comfort and welcomed in the presence of other people. At the end of the day, what counts most is the reality that one allows himself to be an instrument for other people's growth.