This is the default capitalist view. Anthropology disagrees. For much of human history we’ve exhibited altruistic behaviour towards one another. There are plenty of instances of that today: coalitions, unions, mutual aid groups, community volunteer groups… not to mention the individual choices people make in the interests of others over their own.
There is always some selfishness in people but it is a choice to structure society and economic activity around it.
There is always some selfishness in people but it is a choice to structure society and economic activity around it.