rawr. I'm not expressing myself clearly.
Our ability to think and choose to obey or ignore our impulses is what is being called "higher", while those impulses are being called "baser". But that ability is just a function of our overgrown head organ. Some other animals have some of the mentaly capacity we do, but not to our extent. Ours is the best.
Similarly, other animals can do things we cannot - fly, swim squirt ink, whatever - all of which are results of various organs better developed than ours. And all of those animals also have a "best in class" species.
So obviously in some way we are "different" than other animals, and can do things they cannot. The opposite is also true. Take away our best in class brains, and what have we got? Nuthin. We cannot do anything well compared to other animals. We call our specialization "higher", but I really just see it as "different". Otherwise, we would be calling other animals' specializations "higher" as well.
To me, higher and baser it feel like an outgrowth of xian thought which constantly seeks to differentiate between humans and animals on the basis of a soul.
Now, if you want to call that kind of thing higher in terms of brain function - that is, the impulses are subordinated to the decision making part - then I have no argument there. In that context the terminology has different meaning.