Let's say we have a group of high IQ individuals of a sizeable number. In what manner should they reproduce in order to maximise the odds of creating a genetically high IQ population over several generations?
I am currently working on my PhD, and the nature of intelligence (IQ, if you will) is my area of research. The reality is a lot of scientists, educators, and psychologists disagree on nature vs. nurture. The research I agree with (and many more people are also agree with) concludes that intelligence is almost entirely nurture.
People get smarter every generation.
Every generation, people get smarter. As access to public education increases, IQ goes up. That's not nature. That's entirely nurture. People aren't gaining an aptitude for knowledge through genetics, they're learning more. You can increase IQ through learning, making it a useless measure of actual innate intellectual ability.
The genetic component could come from personality. Many personality traits are genetic so it's possible academic drive and persistence could be genetic traits that foster intelligence and lead to more intelligent people. That is something you could utilize as part of your selective breeding program.
Academic giftedness isn't innate in all countries. The United States has been tracking kids into gifted, general, or SPED educational tracks for generations. There's a belief that giftedness is something we are born with, but the data doesn't back up the fact that children are born highly intelligent. Data suggests that having prior knowledge (so learning your ABC's or maybe how to read prior to entering public school) is what makes a child gifted or not. It is learned knowledge, not a genetic difference in the children in gifted programs and the children not in gifted programs.
In many Asian countries, the educational systems value hard work. While there is plenty to be said about how negatively many such systems impact children, the belief that intelligence and academic achievement are a personal choice and can be achieved by all students (with the exception of those with serious cognitive disabilities) is pervasive. And it's reflected in the academic excellence of many Asian students (which is why even in the U.S., Asian students have a higher score bracket/ expectation than all other ethnicities).
How to make your population intelligent. Value education. Begin teaching children to read at 2 and 3 years old (when most children have the ability to learn to read). Make a rigorous curriculum a core component of your schools. Abort children with disabilities or cognitive variance/ disabilities that affect intelligence (or don't allow them to reproduce so that genetic disabilities can be hopefully bred out or at least controlled--look to Iceland for more information on this, 100% of children with Down Syndrome have been aborted in the last 10 years thus there will be a generation without Down Syndrome). If you want a group of people to be more intelligent, have them value intellectualism. The rest will follow.
Theoretically, it is possible to maximise IQ in a population via selective breeding or genetic engineering. However, it is not possible in practice with current levels of knowledge and technology.
1. What is high IQ?
First of all, there is no strict definition of IQ. Recent research suggests that there are different types of intelligence which do not necessarily overlap.
Moreover, IQ tests are often biased and measure erudition, test-taking skills, and knowledge of cultural norms. Some tests (for example, spatial intelligence tests) are a bit more objective but still rooted in cultural traditions.
2. IQ and DNA
We suspect that IQ is somehow linked to genetics. However, we do not know exactly what genes are 'responsible' for high IQ.
Expression of genes can change depending on environmental factors. We do not know the role of epigenetics in high IQ. It can be significant or not.
4. Nature vs Nurture
Research shows that people tend to improve their IQ scores as they take more IQ tests. There is also a tendency for people from higher socio-economic groups to exhibit higher IQ scores. This leads to a question how much impact education, nutrition, and other living conditions have on IQ. It is most likely not 100%, but it can be very dramatic.
If you can answer these four questions, you can employ selective breeding and genetic engineering (any combination of the two, for that matter). Then you can provide the best growing conditions accompanied by stellar education.
You also might want to consider that a society comprising only people with high IQs will be very different from ours. There is a lot of interesting research suggesting that high IQ is associated with distinctly unconventional cognitive and perception patterns and decision-making. Moreover, it is very likely that genius and insanity are connected through the same genes...
If this is earth and the goal is as stated, you use IVF. Embryos with genetically superior genomes (related to intelligence) are chosen over the others for implantation and gestation.
If IVF is not an option, and mating is 'just like mom and dad used to do,' then you would mate the smartest to the smartest. You still have regression, but you measure intelligence in the offspring. And repeat.
Think racehorses. Or any other attempt to create a special breed.
The answer is as much as possible but it still doesn't solve the problem.
The problem isn't the top end but the bottom end. You need the low IQ to stop breeding and in most Western countries, all the low IQ do really well is breed.
Watch Idiocracy to see the best example of the problem in action.
The best way to guarantee a genetically higher IQ population is to stop, lets say, the bottom 25% from having children. Suddenly IQ is a survival trait and evolution kicks in.
That said, genetics is only half the equation. You need better education and child support programs so the people you want to breed can have more children.
On average, it costs $250K to raise and educate a single child. Smart people know this so they have one, maybe two at best, children which doesn't help spread the smart genes.
Realistically, the only way to get a genetically high IQ population is through gene editing designer babies.
First, putting all morality issues aside, IQ can be well defined, and in fact it is, by current intelligence tests. For the purpose of this question simply divorce yourself from the notion that the IQ test has any meaning other than the score ON THIS TEST, it doesn't have to correlate with any kind of life success, survival skill, or moral worth. Consider it like any other breeding program: I want to breed chickens to grow fast and produce the most consumable calories in a given amount of time, like 12 months: Along with a few other economic conditions, like no great increase in disease, injury aggression or self-harm, at least before harvest at 12 months.
To help separate this from knee-jerk responses to controlling humans, let us consider breeding mice for this trait. We will devise a mice IQ test (already been done, I know). Ours will focus on the ability of mice to solve puzzles and make distinctions in patterns.
High IQ would be treated as a good in itself (something we want without having to justify it), and testing would be mandatory before mating would be allowed. Pregnancies without testing would be aborted. Testing at puberty would result in sterilization; or perhaps temporary sterilization (an easy surgery in males, a pill in females) if we wish to allow multiple chances to allow for having a bad testing day.
Breeding could be allowed by choice, just a restricted choice: A female with a desire to mate could be allowed to choose her mate from acceptable mates, for example. We might want a trait in which females prefer smarter mates, and select for that, too.
You could also apply human levels of intelligence to develop the genetic science of what it takes to score high on the IQ test: Correlated genes and gene combinations, for example. Note that we don't have to know exactly what the genes do, in order to use them in the selective practice: We can just assign gene sets to groups of "acceptable IQ" and "unacceptable IQ", and then abort or genetically engineer embryos that have combinations of genes that we have seen in the unacceptable set but do not see in the acceptable set.
Regression to the mean is not some magical property, it is a result of random combinations. By analogy, consider the dice game Yahtzee: A roll of 5 of exactly same number is a Yahtzee. Thus there are six possible Yahtzees. If two Yahtzees are "parents" and we mix 2 dice from one and 3 from the other, odds are only 1 in 6 pairings will result in another Yahtzee: The other 5 pairings result in a full-house (3 of one kind, 2 of another), which is 50 times more common than a Yahtzee.
Thus reducing the randomness of gene combinations can improve the odds of getting mice with high IQ scores on the test we devised.
I will repeat: This is a scientific approach divorced from any morality of controlling the mating freedom of mice, or whatever the subject. Also repeated; there is no guarantee that our test is "well-formed" in the sense that the traits it tests for improve the odds of mouse survival, mouse longevity, or mouse quality of life.
In fact, if you believe evolution, in the last few hundred million years, has already balanced the benefits of mouse intelligence with mouse survival and reproduction, then increasing mouse intelligence probably comes at the cost of reducing mouse survival and reproduction. In evolution there is a chance of stumbling upon a free lunch (as plants did with photosynthesis, and as we humans did with abstract intelligence), meaning one that increases survival and reproductive chances; but if the free lunch is exceedingly rare then the chances of finding it are, correspondingly, exceedingly low.
Of course engineering is in the business of making things that would be nearly impossible to achieve by chance either certain or for more probable: If I am allowed to turn the dice, I can have a Yahtzee every time, instead of averaging just 1 in 1296 throws.
Thus selective breeding and selective genetics can avoid regression to the mean as much as possible, by reducing the randomness of gene combinations to those known to work. In the end, given some very high scoring on the IQ test, simply cloning the winner's DNA will eliminate the chance of DNA being the reason for low scoring, and allow the breeders to move on to other factors (like infant and child nutrition, education, exposure to pollutants and disease, removing stressors known to reduce IQ performance like isolation, frequently interrupted sleep due to noise or other irritants, frequently changing environmental conditions, frequent incidents of physical pain, etc).
This has been done in the past, both unintentionally in the case of the Ashkenazi Jews and as a deliberate plan by followers of the Eugenics movement in the early 20th century.
In the case of the Ashkenazi Jews, the mechanism is thought to be the exclusion of the Jewish population from most forms of remunerative work, and exclusion from the rest of the breeding pool. The Ashkenazi were able to work in complex fields like finance and accounting, and of course the smartest people did the best, became the most desirable mates in the restricted Ashkenazi breeding pool and had the most offspring. Continued through the Middle Ages, generations were unwittingly selected for intelligence, resulting in the Ashkenazi Jews having the highest IQ of any single human population group. The downside of this is they also have a much higher propensity for genetic diseases as well.
The Human Eugenics movement was an offshoot of Social Darwinism, and sought to create superior humans by "design" rather than by accident as in the case of the Ashkenazi. Amazingly for most people, this idea was pioneered and aggressively pursued in the United States by Planned Parenthood, whose founder Margaret Sanger sought to "assist the race toward the elimination of the unfit." This was well in advance of the rise of the National Socialists in Germany.
The issue is twofold. Firstly, we have no readily quantifiable way of measuring intelligence, as the controversies over IQ mentioned in other answers suggest. Secondly, we also have little idea of what mechanisms influence intelligence. Eugenics as practiced by Sanger and others can produce a rather crude increase in intelligence or any other trait, so long as the people running the program clearly define the trait they are looking for and are consistent in their program over generations (centuries in the case of humans). You could breed people with the ability to do well on IQ tests by only breeding people who do well on IQ tests, but that may not actually be increasing the overall intelligence of the population group. (You would actually do better if you were to breed for simple traits like hight or hair colour).
So as a first order effect, by carefully selecting for a trait, consistently breeding for that trait and eliminating people from the breeding pool who do not conform to the desired trait, you could increase the intelligence of that group compared to the population as a whole. The "regression to the mean" would be dealt with by eliminating those people from consideration in selecting the next generation of parents, and inbreeding issues such as suffered by the Ashkenazi Jews can be minimized by recruiting high IQ people from the general population into the program with every new generation.
The irony is you could go through a lot of time and expense only to have a population capable of amazing performance on a limited set of tests but who are otherwise idiots.....
They should reproduce using the usual methods for that population in as close to its natural habitat as possible, while providing a diverse, continually challenging learning environment.
Artificially controlling the environment in a noticeable (to the population) way will cause stress on the population, which, depending on its level of intelligence and level of awareness, may even sabotage the end goal out of fear or rebellion against manipulation.
Left alone to reproduce naturally, individuals will be attracted to others similar or better than themselves in what they consider to be a good example of their species, and more easily produce likewise offspring. This will apply to whatever traits are valuable to survival for that species.
Those species that are already highly intelligent and naturally nurturing to their offspring will benefit from lack of rigid reproductive expectations and have the best chance possible to teach offspring the highly intelligent characteristics of love, compassion, encouragement, resilience, competitiveness, deductive reasoning, learning from mistakes, emotional control, etc. For those offspring that appear to have received less desirable traits, intelligent species will most often still care for them to help them achieve their highest functioning because that trait is considered a trait of a highly intelligent species.
A challenging, diverse environment that includes access to basic survival needs for that species will provide many ways for them to learn and work with these skills to improve their intelligence. Over time, the most intelligent survive at a higher rate than the less intelligent naturally. Then out of this population, you will also achieve more individuals that can score higher on IQ tests.
I'm going to play Devil's Advocate a little: In the land of the blind, the one eyed man is king.
Since IQ is a measure of an individual's performance on a test compared to his/hers/its peers, the best breeding program to ensure one subset of population outperforms another subset is to offer incentives for the people with developmental disabilities to have the most children.
When current IQ tests were developed, the median raw score of the norming sample is defined as IQ 100 and scores each standard deviation (SD) up or down are defined as 15 IQ points greater or less, although this was not always so historically. By this definition, approximately two-thirds of the population scores are between IQ 85 and IQ 115. About 5 percent of the population scores above 125, and 5 percent below 75.
This means that a 100 IQ in todays population is not the same as a 100 IQ 50 years ago nor will it be the same as a 100 IQ 50 years from now since the overall population against which a single score is compared will have changed. If you make the majority of the population little more than drooling idiots, then someone who is merely standard in our world would be a genius in theirs.
Another important consideration is Nature vs Nurture. One study showed that in high income families (which presumably your elite high IQ class would be), genetics only accounted for 55% of cognitive ability, while in poor families it was only 39%. This means that by simply providing the proper environment for the development of a high IQ, your worst case scenario is that your working with a 45%'er that isn't going to improve much.
An additional benefit of making yourself look smarter by making everyone else dumber is that if you end up with a "smart" child that has a developmental disability (eg autism or Down's syndrome), you can relegate its care to someone in the "stupid" class.
*Note, I am not advocating this, nor do I support this. Eugenics is bad.
Kill all the stupid people
selective breeding 101, got to remove the undesirable offspring to reinforce your desired trait in the genepool.
How to create a genetically high IQ population while avoiding regression to the mean as much as possible?
To avoid the leveling drift (regression to the mean) in a population, what you need to do is Hybridize:
A hybrid may occasionally be better fitted to the local environment than the parental lineage and as such natural selection may favor these individuals.
The Bell curve is considerably flattened and shifted to the right - as most hybrids don't survive, but those who can thrive, will.
So a problem occurs if you wish to genetically isolate a particular population - regression to the mean is the least of your worries if there is no selective pressure to improve the population's intelligence.
But I guess you figured that out, so pressure selecting for inteligence to allow for reproduction then:
You'd be looking at a form of licensed fertility in the wider population based on whatever test of inteligence you deem appropriate. So let's test people (Vis a vis: Hunger Games like?) at an age before they can reproduce and depending on the outcome, sterilize them (I posit that enforced death is a form of reproductive sterilisation) or support them to breed.
The various interactions between intelligence and personality traits are more complex than simple hope would wish. It's kinda difficult to select for just intelligence, intelligent aggressive people will likely always have an edge over the agreeable intelligent ones in any kind of spontaneous combat, or competative environment - will you end up with a society of warlords/conquerors or can you develop a methodology that selects for other characteristics?
I feel that rather than answer the question here, I've re-asked it at a slightly higher resolution. Does this framing suit the OP? If not, it's a subject that interests me, let's go further.
So perhaps a conversation for another thread, but what of the emotional quotient or capacity required to see any civilized society through history? There was a time when IQ wasn’t measured.
Here’s the thing, smart people are usually tolerant. Then the intolerant, cruel though clever, see that they will tolerate anything, taking the liberty.
What do you say about the value of EQ of long-standing societies or the nature of high IQ low EQ inevitabilities?