what's a human..?

"What makes us human?"
I love this question, SO MUCH. I have so many things to cite about this, but unfortunately I can't access them all on the school computer.
Let me talk about the human brain for a moment. I'll use the archaic term "limbic system" to refer to the primitive part of our brains. The human cerebrum is fascinating and has many parts- what I'm trying to talk about is the oldest, the reptilian part. What do I mean by that?!?! Well, the brain evolved outwards from the very start of life, from merely a stem to a huge amount of diverse systems. The reptilian brain is responsible for our primitive urges (pleasure/addiction, fear, territoriality, etc.) and exists at the very center. Our brain is made of multiple tiers of systems, showing us a timeline of how we evolved over the millenia. This is actually a controversial theory and is challenged by new research showing us that bird and reptile brains are more complex than we initially thought.
But before I run myself into walls contradicting myself over and over again as usual, the theory I proposed here does have at least a LITTLE truth to it. And we know for sure that certain parts of the brain of a human are not unique to it.
So what IS unique to a human brain? What makes us superior?
Define superior: "human" characteristics such as reasoning, curiosity, ingenuity, culture, language and dialect are found in other animals. Dolphins, corvids, cephalopods, and elephants, to name a few. But it is indeed our culture which allows us to prosper; our lifestyle is supplemented in great part by the agglomerative nature of our inventions. You could say that written word is what makes us human, if not for the fact that countless cultures have developed very sophisticated societies without it. Our language for sure is an incredible feat, especially because no one invented it! Dolphins and elephants, however, are found to develop unique languages specific to their social group. Dolphins, when encountering another group, must learn the other dialect before being able to communicate with them- so a dolphin's language is a big part of its culture. So, though humans have what is certainly the most diverse and inclusive of animal communicative systems, they are not unique.
But what about logic? Logic is the hardest of human traits to define as animal. Perhaps logic and reasoning is what makes us human? These things are found present in lesser degrees in the animal kingdom as well, however. Dogs can be taught to count, and even humans went a very long time with no concept of counting or 0. I'll end with a few quotes.
"The simplest thought, like the concept of the number one, has an elaborate logical underpinning. The brain has its own language for testing the structure and consistency of the world." -Carl Sagan.
"There isn't a sharp line dividing humans from the rest of the animal kingdom. It's a very wuzzy line, and it's getting wuzzier all the time." -Jane Goodall (I hope so anyway. these quotes are ones i remember.)


Anyway I spent more time talking about what makes us animal than what makes us human here. What do you think, guys? Am I a hapless blowhard? What do you think makes us human, or animal, for that matter?