The Molecule That Shaped Society

Oxytocin.  It is a hormone that performs many functions in mammals, most notably the binding of mothers to their families, particularly their children.  It looks something like this:

Given its function, we could actually call it 'the empathy molecule.'  It is what makes people feel the joy and pain of other people.  It increases trust and reduces fear.  Hence, its role in familial binding is obvious.  But the implications of this are far-reaching.

The family unit is a microcosm of society as a whole.  Society is, of course, made up of families.  And society is, just as obviously, defined by the myriad social interactions of its members.  We all have certain norms and expectations of those interactions, independent of our culture.  For example, when having a conversation, you do not expect the other person to pull out a knife and stab you.  It is oxytocin that defines these norms - mostly based on empathy.  Therefore, we could say without exaggeration that oxytocin is the molecule that shapes society.

Indeed, the inability to secrete it is linked with psychopathy and sociopathy.

Since our happiness (or any emotional state) is simply the balance of such molecules in our brains, it's important to pay attention to what they are, why they are secreted, and how they interact with each other.  Ignoring or fighting our own biochemistry is a losing battle.

Paul Zak gave a great TED talk on exactly this: