Humans are animals. Natural life is divided into only two categories: plants and animals.
Humans live just like any other animal on this planet. They are intelligent animals, making use of tools and, abstractly, their minds. A human's brain is more like a tool than anything else. As such, different humans will rely in differing amounts on their brain. Some other intelligent animals do that too, the only difference is that humans have a really evolved thinking.
The only thing that distinguishes humans from any other animal is their bipedalism. It is a theory that because humans went bipedal that they turned their evolutionary focus on the brain.
A lot of things some people consider "human-specific" actually are not human-specific. Here are some small examples:
- the ability to use tools/surroundings. Clearly not, we know certain monkey species use tools. We also know some birds make use of tools or surroundings. Crows for instance, are one of the most intelligent type of bird. I personally witnessed a crow using a bowl of rain water to soak a piece of hardened bread just so it could eat it easier.
- the ability to form empathic links. We already know elephants do that. I don't know much else, but I'm pretty sure we might not even comprehend some forms of empathy that may exist between certain animals.
A common misconception that takes this point to the other extreme is that dogs can form empathic links with their masters. That's pretty false, because dogs only agree to be subjected to their masters command for the promise of food, water and shelter, sometimes fun (particularly in younger animals).
- the ability to make decisions. Borderline decisions are hard to come by in the animal world, so it's really hard to study this aspect. Even if you have specimens of the same type that react differently to a situation, how can you be sure their decision was based on any kind of thought?
Applicable to humans, as well. Let's examine a simple case of "should I do this or not". Give someone an abstract choice between two possible paths. They may do any of the following, predispositions depending on other factors that make up their character: randomly pick one path, pick the path he or she believes brings the best advantages, or pick the path that brings more disadvantages, just so they can show that they can do that.
The first two paths are paths any animal might take. The third path may appear to be special, but that's not the case. The subject may have taken the third path to show off, or whatever reason. For them, that whatever reason will now constitute an advantage which may make the third path more advantageous to them than the other, thus creating a paradox, since they now actually fall within the second path
Which begs the general question: Just how many of our decisions/choices/etc. are any more than factor-driven?
To be honest, I think that the problems humanity creates stem mostly from their numbers. If the world had 1 10th of its population, than a lot of today's issues would have been much smaller, our impact on the planet much smaller, etc.
That's why I hope than when and if mankind finally colonizes other planets, they manage their numbers.