For an attraction to be “universal” (as qualified here) it must have been in the human genome for a very long period of time. And such DNA would remain there only when the attraction actually supported survival for that very long duration. Because primal environments varied over both time and geographic area, the survival essentials of diverse human settlements would also have varied. Swimming might have been critical for one group and mountain climbing for another. But neither would have been essential to everyone at all times such that the universal genome got that preference.
However, all people had in common a set of generic survival essentials. Such as movement. So the swimming group and the climbing group shared a common generic necessity: plenty of physical activity. Hence affective evolution imprinted a universal attraction to mobility in general, rather than any specific type.
Further, such a generic attraction is best for survival in a world that requires diverse forms of movement. A primal habitat might require swimming and climbing plus many other types of mobility, so a general attraction to movement would be optimal. Similarly, a nomad born with an appetite for food generally will survive better than if their attraction is limited to only root vegetables or meat. Some edibles may not always be available because nomads regularly transit different environments. Likewise, a nomad born with a generic attraction to a wide variety of social connections, including those that are casual and those that are intimate will be more likely to survive than one born with a preference for just one type of relationship. So our universal preferences will tend to have a generic quality.
These points reveal why the list of innate primal attractions and aversions is relatively limited. Only a couple dozen generic experiences (depending on how they are counted) were critical to the survival of our ancestors for vast periods of time and in differing habitats. Fortunately, archaeology and anthropology have identified them, and they include the features I’ve just discussed, such as movement, dietary variety and social connection. But there are many others which I discuss in the Primal Uppers section.
Some advocates of a primal perspective tout very narrow “primal” guidelines not substantiated by our knowledge of the ancient past. One commentator calls that “paleo fantasy”. (See Marlene Zuk, Paleofantasy: What Evolution Really Tells Us about Sex, Diet, and How We Live, 2013.) To prevent that, primal guidelines must be generic in scope.
So the best paleo diet follows the general themes of the ancestral diet, because science has identified only its generic characteristics, such as that our ancestors ate a very wide variety of fruits, vegetables, nuts, seeds, and animal parts, and not any particular item in those food groups. And of course we know for sure that they ate limited salt and sugars, and no foods produced in factories. So a diet consisting of a wide variety of naturally produced food is about as specific as a true paleo diet could get. Science may identify more specific dietary guidelines that benefit us and are worthy of following, but unless they are tied to specific universal features of our ancient past, they do not deserve the label “primal” or “paleo”. In my work I try to avoid the over-specificity problem because I define primal uppers and downers based only on the macro elements of the nomadic hunter gatherer lifestyle, those that science knows for certain to have existed for a long, long time.