Uchiyama et al. have provided a valuable explanation of some of the limitations in trying to draw useful conclusions from observations of correlations between sequences in genomes and the behaviours and life course of the individuals who possess those genomes.

The behavioural genetic findings and techniques exist, however, and it's not surprising that the scientists involved are keen to see the fruits of their investigations put to good use. Their findings may not be applicable to all populations, but it's tempting to hope that they could be applied in the WEIRD (western, educated, industrialized, rich, and democratic) populations that best match those in which the research was performed.

One of the roles that culture plays in human lives is the coordination of effort. Throughout human evolution, the most successful groups were those that evolved rules, customs, and beliefs which encouraged people of different ages and abilities to work effectively together to further their own interests and those of the group as a whole. Our ancestors accomplished this without knowledge of genes, but in small-scale societies elders could observe youngsters as they grew up, see which skills they found easiest, and encourage them to develop their talents in ways that would be useful to the group. Such minute observations aren't possible in the educational institutions attended by children in WEIRD populations. So, could information from genetic testing fill in the gaps? If teachers were able to guide pupils towards the educational and life choices which they will find most fulfilling, their efforts would be applied more effectively and society would be better coordinated.

This is a nice idea in theory but it's unlikely to be to be very helpful in practice.

It's not the lack of genetic information that prevents children in WEIRD populations being helped to make appropriate educational and life choices. It's more to do with the cultures of WEIRD populations and the many ways they have evolved that hamper the effective coordination of effort.

For example, American culture includes the dogma that free choice and hard work are highly valued. Children are often told that they can choose from a wide range of possible futures and urged to have faith that, if they work hard enough, they will realize their dreams. In fact, children's choices and their success are severely limited not just by the genes they inherit from their parents but also by the culture that they inherit from the family and community they grow up in and via the media they are exposed to. It is their culture that provides the expectations, values, goals, opportunities, rewards, and so on that motivate humans.

If American culture truly valued hard work, wouldn't the members of society who do essential work that is difficult and unpleasant, such as the production and processing of food, receive better compensation than those who, for example, perform research and teach at a university?

Perhaps, few Americans actually believe the dogma about free choice and hard work, but its frequent repetition still serves to inhibit the development of programmes aimed at reducing inequality.

It's not just poverty that limits freedom of choice for young members of WEIRD populations. Imagine, for example, the opportunities available to a female as she graduates from high school. One choice she might reasonably consider is becoming pregnant. At this age, her body is in peak condition for maternity and it's likely that her own parents and those of the potential father of her baby are still young and fit enough to help her care and provide for her baby. In some communities within WEIRD populations a young woman's ambition to be a mother could be realized, but in others women are expected to want to go to university, establish a career, and own a home before even thinking of motherhood. Their parents are too busy with their own careers to take on any grandparental duties. The work of raising the next generation is considered to be of relatively low value in the cultures of WEIRD populations. Not surprisingly, the fertility rate of these populations is below replacement.

For the last few generations, cultural change has been very rapid in human populations and our species has become very successful in the sense that the human population has grown rapidly. But it's now more than apparent that in the course of modernization populations evolve a number of cultural maladaptations that prevent the effective organization of labour and use and distribution of resources.

Modern societies are currently neither demographically or environmentally sustainable. Many of them suffer other kinds of social dysfunction. The classical eugenicists looked to genetic evolution as a source of human problems and solutions. They were looking under the wrong rock. Humans are far more variable culturally than genetically and, even though both genes and culture are hard to change, culture is by far the more tractable. Our ancestors have been finding cultural solutions to their problems for many thousands of generations and our descendants will carry on the tradition. Uchiyama et al.'s useful dive into the relationship between genetic and cultural inheritance and evolution shouldn't encourage us to forget the practical bottom line.