All human beings, as well as animals, occupy a variety of spaces. We all live in a personal space that surrounds us like a transparent bubble. Our personal space is like a second skin and helps form a safe boundary between ourselves and everyone else. When someone else comes too close, we may become irritated, afraid, or suspicious. Personal space is influenced by many different things.
Age has significant impact on personal space.
Different cultures often also have different rules about how much personal space is required for politeness. Sometimes not understanding another person's need for personal space can lead us into difficulties. We can also decide to expand and contract our space to fit different occasions. On a subway train or a crowded elevator, people sometimes have to stand or sit very close together. They think of you as someone who is invading their territory.