Human behavior is based on two basic instincts inherent in it genetically. This is the survival instinct and the reproduction instinct.
Whatever a person does in his life, all his actions, feelings, emotions are based on these two instincts that help him survive and continue his kind, that is, serve his personal interests, his “ego”. A person’s selfishness is the fundamental motive of his behavior.
In this case, the question arises: why do people show solidarity, that is, active sympathy, assistance, assistance to any groups of people based on common interests, goals and views.
For example, there is professional solidarity when workers, sometimes even seemingly to the detriment of their personal interests, defend collective demands, participate in strikes and refuse to work out of solidarity with their dismissed colleagues.
The fact is that a person, showing solidarity, actually continues to take care of himself and his personal interests, because he protects his colleagues in the hope that later these colleagues will also protect his interests and support him.
Thus, solidarity is nothing but a deferred and veiled concern for oneself in the future.