[jonnathanson]

This is incredibly true.

But I'd add/caveat that I've seen (and, unfortunately, worked for) plenty of startups that write up a "cultural code" -- typically, a big-ass document that gets posted on a wall somewhere -- and then completely ignore or violate its tenets.

Culture is a living, breathing thing. It's not just a mission statement. It needs to be carried out, and if it's not, then all the mission statements and codes in the world won't force culture into existence. If anything, they'll be revealed for the farce that they are.

And it really does flow from the top down. As the founder, or as a founding exec, you have to eat your own dogfood. You are not above the culture. You are not above the laws of your own land. If you set cultural guidelines and expectations, you are the first person people look to to see if those guidelines are being put into practice.