While human progress came from natural selection working on beneficial mutations,

there are more deleterious mutations than beneficial mutations. Evolution is also the sifting out of harmful mutations that occur in every generation.  Human evolution, both the enhancement of the good and the winnowing of the bad, has now stopped due to the rise modern medicine and the welfare state.  Mutations continue, though, so in theory the human genome is going backwards now.

So if there are far more deleterious mutations than beneficial ones each generation, how did we get a far as we did?  How that happened is detailed in Gregory Clark’s “A Farewell to Alms.”  Human society has traditionally been run as a meritocracy with assortative mating amongst the more productive members of society.  Pre-contraception, more productive members of society had larger families than less productive people who barely scraped by.  So, while everyone suffered from the same mutational load, the effects of assortative mating could overcome that and the genetic makeup could improve.  The replacement fertility rate to keep population steady is considered to be 2.3 children per woman.  That is purely in terms of numbers.  Including the mutational load, the number might be 2.5 or higher.

There are big differences in productivity among individuals in our society.  Actually it has always been thus.  To develop our big brains and support their large energy demand, humans developed pair bonding, non-procreational sex, menopause and a number of other things to ensure a constant food supply to babies and infants who would otherwise suffer brain damage due to periods of malnutrition.  One of those adaptations was group food pooling behaviour.  In Palaeolithic tribes in the tropics and temperate regions, men, hunting in a group, would bring in about half the calories.  The game they brought in would be divided up among the families in the tribe equally such that all the children lived in nutritional homogeneity.  No matter how good a hunter might be, his children fared no better than anyone else’s.  This evened out hunting success, which is patchy for big game.  By comparison, the nutritional state of chimpanzee infants is directly related to their mother’s foraging success.

The alternative would be for individual hunters and their families to catch and kill their own.  But even the best hunter would have days on which his children went hungry with consequent brain damage.  At the same time there was no incentive to work harder.  Hunting got you killed and if you kept working, then you were just feeding someone else’s family. A consequence of all that is that evolution was very slow.  There was group selection and we can see that in the displacement of the Neanderthals and others.  But the selection pressure within the group was slight.

So our antecedents invented a form of communism to keep the children fed. That held sway for a couple of million years right up to the invention of agriculture, which turned everything on its head.  Hunter-gatherers had no way of storing food.  Agriculturalists could store large quantities of grain that would carry them through the bad patches.  Suddenly, instead of extra work getting you killed in a hunting accident, the more work you did, the more likely you were to survive.  Human evolution sped up dramatically post the invention of agriculture only 10,000 years ago.

The proclivity to work or not work has a genetic basis and the genes are close to being identified.  The fact that there is a laziness gene in the human genome shouldn’t be a surprise because there are genes for other things such as violence.  Thankfully, the violence genes were largely rinsed out of western society over the last thousand years thanks to the execution of murderers by the state, as detailed by Steven Pinker in “The Better Angels Of Our Nature: Why Violence Has Declined.”   One thousand years ago, England had a murder rate similar to that of current day Afghanistan, which is thirty times higher than the current English murder rate.  What happened in between is that the English judicial system rinsed out most of the genes for impulsive violence.  Afghanistan and places like it never had that rinsing and thus they have a genetic disposition to much higher levels of violence than what we are used to. 

Thus it also follows that if you bring people into the country who have never had their Neolithic genes for violence rinsed out of their genome, their intrinsic propensity for violence will collide with our legal system resulting in a higher rate of incarceration.

Human diversity is something to be celebrated, so we are told.  One major kind of diversity is in the range of human intelligence, with the Bushmen of southwest Africa at the bottom end with an average IQ of 60 and Ashkenazi Jews at the top end with an average IQ of 115.  Ashkenazi Jews have had assortative mating for intelligence for more than a thousand years, as an end in itself for a community that valued learning.  That started to pay off in the mid-19^th century when they exploded out of the ghettoes with the introduction of competitive entrance exams to the professions. 

Human intelligence is 70% heritable.  It is also equated with productivity.  That effect is being leveraged by technology.  When we all worked in the fields, we had to stop work when it got dark.  Then came the electric light and we could work after sunset.  White collar workers had to go home, though, because the office was closed.  Then came the internet and we can work any time of day or night to our heart’s content.  So for those who have a good work ethic gene and are intelligent, the internet has leveraged both those things.  Thus the French socialists have banned work emails after normal hours of work -- they don’t like the idea of anybody trying to get ahead.

On top of all that there are cultural factors.  Culture enables the adult males to work together and not waste their time fighting over the females as the other primates do.  Ok, the bonobos don’t fight over their females but they are not going anywhere either.  Religion is a part of culture and it is no accident that people who have faith outperform people who don’t.  Counterintuitively, that notion would be distressing to the people who celebrate diversity.  It is largely cultural factors that explain most of the divergence in standards of living around the planet.  The OECD countries have about four times the standard of living of the best of the rest, with no country in the gap between.  At its simplest level, that gap is explained by respect for private property. 

Cultural factors will also determine whether or not a country will work at all in the first place.  The cultural critic Steve Sailer was able to predict in 2003 that the invasion of Iraq would not work due to cousin marriage.  Too much cousin marriage means that tribalism triumphs over national unity.  So it came to pass and Iraq, without a dictator, has split on tribal lines.  All the waste of blood and money on nation-building there could have been avoided by a proper understanding of culture.

In all our human diversity, there are people who have strong expression of the laziness gene because they didn’t have much of an agricultural period to reverse the Palaeolithic proclivity for resting up after a meal, people who are inherently violent because they missed out on a good judicial rinsing out of the genes for violence, and there are also people who are not very bright because that wasn’t selected for in their evolutionary past.  Some people have all three of these traits at once.  These people are triply cursed.

If follows that if you let these sort of people into the country then the country will go backwards in terms of standard of living, crime rates and social cohesion.  We can skip having a debate about it though because the country is already full enough with a declining margin of safety in terms of carrying capacity.    

David Archibald, a visiting fellow at the Institute of World Politics in Washington, D.C., is the author of Twilight of Abundance (Regnery, 2014)