I am in full agreement with almost everything Pigliucci says in the above-linked essay about "human nature." I am concerned, however, about what I see as his opinion that a good (unified, comprehensive?) theory of cultural evolution may one day be established.
"...despite much interest and a number of valiant efforts — we really don’t quite have a good theory of cultural evolution at hand."
Though he doesn't directly address the reasons for this lack of a good cultural evolutionary theory, Pigliucci is right about this.
The lack of a "good" cultural evolutionary theory, however, has less to do with our not yet coming up with one than it does with our scientistic expectations. That is, the incorrect belief and insistence that the patterns and practices of human cultural adaptation, extant cultural adaptations and all of those throughout history and prehistory, are reducible to a unified theory containing equations, formulae, and genetic mapping in a manner similar to what mathematics, physics, chemistry, and biology apply to other phenomena.
An illustration of only a fraction of the ideas in the Ethosphere and our commentary on them. This graph represents co-citation patterns based on all articles published between 1993 and 2013 in Nous, the Journal of Philosophy, the Philosophical Review, and Mind. Photo Credit: Philosophy@MHS
Culture and cultural evolution are not fully explained by the Darwinian-Mendelian theory of biological evolution, or more recent related efforts called evolutionary psychology and memetics. Worse, the approaches taken and speculations used in most of these two latter-day efforts are misinforming the public.
Ideas such as beliefs and values and their attendant and complex social relations such as marriage, family, and broader group relations, and the rituals, institutions, codes, and laws that, in turn, attend to them, have different properties from those of atoms, molecules, cells, tissues, organs, bodies, and species.
Cultural phenomena, both within a society at any point in time and through time, and comparatively between societies over large expanses of time, are artifacts of human mental life. They are created, shared, enforced, upheld, maintained, revised, and/or rejected within ever-fluctuating environmental and social and historical contexts.
There is a similarity between cultural phenomena and atoms, molecules, and species in that all are acted upon by conditions and processes in their environments. The difference is in the type and nature of their respective environmental conditions and processes.
Physical environmental contexts are at work on matter, biological individuals, and on cultural phenomena. However, over time the cultural adaptive strategies of individual societies and Humankind as a whole have led to the emergent development of an immense, complex, worldwide cultural environment – an Ethnosphere*. This cultural domain influences the ideas and values of every human society and their constituent individuals.
Non-human species are impacted by the physical environment. The decisions and other behaviors of individuals also influence individual and group survival and reproduction. Cultural phenomena are not completely comparable to matter and species. They are subject not only to the same physical and social influences at work on matter and species, they are also subject to the history and prehistory of ideas.
Take fire, for example. Its controlled use by our human ancestors began almost half a million years ago. Archaeological evidence shows that it was initially used by Homo erectus for warmth, lighting, and perhaps cooking and protection from predators. Later, fire was also used to facilitate stampede-ambush hunting. Since those earliest times, there has been a gradual increase in the quality and quantity of ideas about the nature and uses of fire. Since its initial use and spread between bands any new idea about fire has not only been subject to its potential influence on and from the environment, and on the viability and reproductivity of human groups, it has also been subject to the full range of historical and prehistorical ideas, codes, laws, and behaviors pertaining to fire. Fire usage, once it began and was retained as a worthwhile adaptive stategy, was thereby added as a subset of the totality of Humankind’s cultural knowledge. Eventually, the knowledge of and behaviors associated with fire became part of the cultural repertoire of all human groups via cultural diffusion or independent invention.
Trying to evaluate and understand the essence or fundamental nature of fire only (reductively) in terms of its relationship to the physical environment (matter), or fireness" as might be found in genes and neurons, or from fire's potential impact on individual and group survival and their biological fecundity, is ludicrous.
Fire ideas may be, to a degree, successfully subjected to the above approaches. However, and far more importantly, ideas about fire are also subject not only to the current market place of ideas (itself an environment separate from material physicality and bio-repro), but to all market places of ideas throughout cultural evolutionary history.
Pigliucci is right. Physio-chemical reductionism (materialism) is insufficient on its own and the Darwinian clone memetics is a misplaced metaphor ineffectively posing as a biologized theory of culture and cultural evolution.
Will there ever be a physical/genetic equation or formula for, or Darwinian explanation of, cultural evolutionary processes and their expression in human lives, past and present? I am doubtful. The best minds in the social sciences over the past century and a-half have failed to reduce this vast cultural complexity, this Ethnosphere, to a "good" unified theory.
I see a parallel between this failure and the failure, so far, to solve the brain-mind problem. The levels of complexity inherent in the entirety of cultural phenomena and their processes and manifestations, past and present, are directly expressed, in large part, in the mental life of the contemporary human individual.
Such information, for the most part, can be "held," "carried," and manipulated by the brain but deep notions about fire and its use are embedded not in our nerve cells and genes, rather in our archaeological sites, textbooks, and libraries. In practical terms, each person born into a society, aside from the most basal neurologically reflexive responses to the bright light and intense heat of fire which he is born with, must learn the complexities, nuances, and utility of fireness and all other cultural phenomena of his society anew – from others.
* "Ethnosphere" - "[Y]ou might define the ethnosphere as being the sum total of all thoughts and dreams, myths, ideas, inspirations, intuitions brought into being by the human imagination since the dawn of consciousness." https://www.wordnik.com/words/ethnosphere