As set out in the first post in this category, evolution imprinted into the human genome a set of primal likes and dislikes that I described as “universal”. But that word is overbroad; in this post I flesh out the detail that the brevity of the first post did not permit.
For example, as a general proposition I say that because movement was essential to the survival of hunter gatherers for vast time periods, affective evolution would have selected for people attracted to movement, because such affect fostered survival on the primal plains. People averse to lots of movement would have died out, leaving a population who enjoyed hiking the grasslands, climbing trees and digging for tubers. And we got those genes.
But is that true of everyone?
The answer is no. In the distribution of any human trait there is variation. Consider our height. Some people will be very tall and others very short, with most clustered around average height — the typical bell curve. The same is true of our primal likes and dislikes. Some people are born with a very strong appetite for physical activity, drawn to playing sports, dancing, yoga, gardening and hiking. Others are born with genes averse to movement. These couch potatoes prefer office jobs where they sit at a desk all day and then go home and binge watch television series or curl up with a good book.
But in the same way that human height clusters in an average measure, so does our primal preference for movement. Most people will have some amount of that attraction. How much? Another key principle of affective evolution is that the strength of any primal inclination is proportional to the ancient survival importance of the preferred experience. Because eating and sex was (and still is) critically important to the survival of our species, the average attraction to those experiences is very strong. Movement was important, but less essential. A nomad could survive weeks without moving much but just days without food, so we innately like food more than hiking. But just as few people dislike eating, few are innately drawn to long bouts of sitting.
Like my mother, you might be one of the outliers. She challenged the idea of affective evolution because she could detect very little or no appetite for movement within herself. As I will discuss shortly, low levels attractions to primal experiences can also be explained through social conditioning and not genetic disposition, so I will never know whether my mother was born with her preference or learned it. But evolutionary principles say she could have been born with it.
So with respect to any single primal preference that I claim as universal there will always be genetic exceptions in every population. But, and this is a key point, we have innate attractions to a range of primal experiences, not just one or two. So an outlier in one is likely to be closer to the average in many others. I may be very tall or very short, but am likely to have roughly average eyesight or intelligence. The same is true of my primal preferences. I may innately dislike hiking and climbing trees but chances are that my genes are drawn to bonded small groups or natural environments.