>I'd argue that it's actually our suppression of urges and behaviors that sets us apart.

Oh yea that's deff a unique quality we posses, but our ability to reason and control our urges and instincts only comes to play thanks to our ability to understand and assign meaning to things rendering them as more detached from us. Being able to understand something is having power over it, is what I'm trying to say. It seems everytime I try and understand how we came to our sentience and grew all our qualities that define us as unique, it always comes down to the the same thing.

Have you heard about the theory of Bicameral Mentality by Julius Jaynes? Very interesting read highly recommend you check it out.