Grey is good, because many of the "dichotomies" we set up in our view of nature are little more than convenient conceptual traps. This problem becomes particularly apparent when we use words, like instinct, that have many shades of meaning. Instinct, for example, can mean species-specific, present at birth, independent of experience, automatic, or driven from within. These definitions in themselves need defining, and the debate can rage on and on, with whatever conclusion we wish. Its all great fun, but might lead to never ending circles, or worse, spirals of logic.
To evolve from mere instinct, in whatever definition, has indeed been a hallmark of much that we call human. But if we take "instinct to its 'highest power'" we remain rooted within some deep biological core. That is much of what evolutionary psychology appears to grapple with. Just how far are we "emancipated" from the capturers of our past? Are there circuits in the human mind/brain that allow at least what Paul Tillich called "finite freedom"? What is freedom anyway? Its certainly not a world without structure, but also not a world that drives us down single inevitable channels. Finite freedom is grey.
Thomas Moore has written wisely on human experience. The links between experiences within and the objective, measurable world remains a fundamental challenge. It may always remain so. We FEEL free, but in a manner that we recognize as essentially US (thus constrained), and so on. Total freedom has no structure at all. So here is the grey area of our lives.
A common trap, which E.O. Wilson has addressed eloquently, is to confuse origins with present circumstances. Evolutionary roots do not in any way deny individual life paths, or cultural distinctions, or the fact of experience. Human links with other members of the animal world do not deny that humans, as each species, is also unique. In philosophical language we are a special and natural "kind". But we are not isolated from other special and natural kinds. Nor is our history (this is the key point) devoid from attachments in form, function and cause from other natural kinds.
A number of years ago, when I had the opportunity to raise such matters with an aging Carl Jung, he suggested to me that one problem with the study of humans is that they (we) indeed seem to be at the top of the heap with respect to the richness of our inner lives. Of course such things are hard to "prove". But his simple point was that in animal studies (my field) one can almost always find bracketing cases, examples where skills, etc. are both more and less developed. This is hard to do when we think of human language, or art, or music. Our comparisons are but one way.
I see no reason not to assume that the human brain has developed (evolved) remarkable capacities for flexibility, and even the "freedom" to hold more basic impulses of breeding or fighting in check. At least for a while. There is a growing body of thought that this holding in check may only work for limited periods, and with potentially serious health consequences. Jung was one who promoted the idea of balance between the "rational" and "non rational" (NOT irrational, a different idea). "Rational" humans who try to lead lives as fancy computers that can be reprogrammed at will too easily crack under the strain. Strain of what? Perhaps the strain of trying to liberate oneself too fully from the very roots of human construction.
I see no reason to doubt that humans have at least evolved a capacity to live "beyond claw and tooth", but this will be most likely (my personal religion) if we acknowledge, rather than deny, the claws and teeth of our psychological heritage.
I do not let evolutionary theory mess around at all with my appreciation of sunsets or emotional joys I can share with friends. As Mark Twain noted, it is quite remarkable that people will sit through concerts, and even pay to do so! One can but wonder what deep core of humanity is being tapped here. Need it be devoid of evolutionary roots? I do not think so. In fact, maybe its precisely the search for these deeper roots, and the means by which they have been transformed in our relatively recent past as a species, that will add to joy rather than detract from it, and promote health rather than squash it in one or another mad race to some more arbitrarily defined cultural goal.
I suspect most of us feel we have some vague sense of what is going on, but even that is hard to pin down. Black versus white dichotomies are almost certainly simplistic; we need to grasp the full rainbow of greys in human potential. I see that goal, unattainable in its full form, gaining rather than losing strength from a more full appreciation of biological heritage.