GENETICS

Genes could determine intelligence, but what about cleverness?

Genes contribute to intelligence, but only broadly, and with subtle effect.

First, let me tell you how smart I am. So smart. My fifth-grade teacher said I was gifted in mathematics and, looking back, I have to admit that she was right. I’ve properly grasped the character of metaphysics as trope nominalism, and I can tell you that time exists, but that it can’t be integrated into a fundamental equation. I’m also street-smart. Most of the things that other people say are only partially true. And I can tell.

A paper published in Nature Genetics in 2017 reported that, after analysing tens of thousands of genomes, scientists had tied 52 genes to human intelligence, though no single variant contributed more than a tiny fraction of a single percentage point to intelligence. As the senior author of the study Danielle Posthuma, a statistical geneticist at the Vrije Universiteit Amsterdam and VU University Medical Centre Amsterdam, told The New York Times, “there’s a long way to go” before scientists can actually predict intelligence using genetics.

Even so, it is easy to imagine social impacts that are unsettling: students stapling their genome sequencing results to their college applications; potential employers mining genetic data for candidates; in-vitro fertilisation clinics promising IQ boosts using powerful new tools such as the genome-editing system CRISPR-Cas9.

Some people are already signing on for this new world. Philosophers such as John Harris of the University of Manchester and Julian Savulescu of the University of Oxford have argued that we will have a duty to manipulate the genetic code of our future children, a concept Savulescu termed “procreative beneficence”. The field has extended the term “parental neglect” to “genetic neglect”, suggesting that if we don’t use genetic engineering or cognitive enhancement to improve our children when we can, it’s a form of abuse. Others, like David Correia, who teaches American Studies at the University of New Mexico, envisions dystopian outcomes, where the wealthy use genetic engineering to translate power from the social sphere into the enduring code of the genome itself.

Such concerns are longstanding; the public has been on guard about altering the genetics of intelligence at least since scientists invented recombinant DNA. As long ago as the 1970s, David Baltimore, who won a Nobel Prize, questioned whether his pioneering work might show that ‘the differences between people are genetic differences, not environmental differences’.

‘Complexity catastrophe’

I say, dream on. As it turns out, genes contribute to intelligence, but only broadly, and with subtle effect. Genes interact in complex relationships to create neural systems that might be impossible to reverse-engineer. In fact, computational scientists who want to understand how genes interact to create optimal networks have come up against the kind of hard limits suggested by the so-called travelling salesperson problem.

In the words of the theoretical biologist Stuart Kauffman in The Origins of Order (1993): “The task is to begin at one of N cities, travel in turn to each city, and return to the initial city by the shortest total route. This problem, so remarkably simple to state, is extremely difficult.” Evolution locks in, early on, some models of what works, and hammers out refining solutions over millennia, but the best computer junkies can do to draw up an optimal biological network, given some input, is to use heuristics, which are shorthand solutions.

The complexity rises to a new level, especially since proteins and cells interact at higher dimensions. Importantly, genetics research is not about to diagnose, treat or eradicate mental disorders, or be used to explain the complex interactions that give rise to intelligence. We won’t engineer superhumans any time soon.

In fact, all of this complexity can work against the ability of a species to evolve. In The Origins of Order, Kauffman introduced the concept of “complexity catastrophe”, a situation in complex organisms where evolution has already been optimised, with genes interlinked in so many ways that the role of natural selection becomes diminished in stepping up fitness for a given individual. In short, a species has tinkered its way to a shape that it cannot easily evolve, or improve upon.

Not in the genes

If complexity is a trap, so too is the idea that some genes are elite. In the 1960s, Richard Lewontin and John Hubby made use of a new technology called gel electrophoresis to separate unique variants of proteins. They showed that different versions of gene products, or alleles, were distributed with much higher variation than anyone had expected. In 1966, Lewontin and Hubby came up with a principle called “balancing selection” to explain that sub-optimal varieties of genes can remain in a population since they contribute to diversity. The human genome works in parallel.

We have at least two copies of any gene on all autosomal chromosomes, and having varying copies of a gene can help, especially in immune-system diversity, or any cellular function in which evolution wants to try out some riskier thing while also maintaining a version of a gene that is tried-and-true. Other times, genetic variants that might introduce some risk or novelty can piggyback or hitchhike along with a beneficial genetic variant. If there is an implication for human intelligence, it is that genes have a parasitic quality of scheming off one another; none is superior so much as its utility is developed by exploiting its fellow genes.

Importantly, we have known for a long time that 30,000 genes cannot determine the organisation of the brain’s 100 trillion synaptic connections, pointing to the irrefutable reality that intelligence is, to an extent, forged through adversity and the stress of developing a brain. We know that evolution bargains in trade-offs of risk for advantage, which is why, I believe, we will always carry genetic variations that risk autism, obsessive-compulsive disorder, depression and schizophrenia; and it is why I believe that the neoliberal view that science will eventually solve most mental-health problems is almost certainly incorrect. In evolution, there are no superior genes, only those that bargain some risk, and a few that are optimal for particular environments and tasks.

I wish I could believe that writing is in my genes, but the novel is only hundreds of years old, not long enough for evolution to be selecting novelists, per se. The truth is that writing takes hard work, and writers can exhibit psychological traits that are otherwise a disadvantage – such as neuroticism, or relentless self-examination. We all understand and share these traits to an extent. Evolution has taught us the brutal fact that nature is most competitive when the comparative fitness between competitors is the slimmest. In light of that, the wealth inequality that has emerged in recent decades is not a validation of yawning biological gaps – it is driven by our need to justify an illusion of superiority and control.

Trust me. I should know.

This article first appeared on Aeon.

Support our journalism by subscribing to Scroll+ here. We welcome your comments at letters@scroll.in.
Sponsored Content BY 

Following a mountaineer as he reaches the summit of Mount Everest

Accounts from Vikas Dimri’s second attempt reveal the immense fortitude and strength needed to summit the Everest.

Vikas Dimri made a huge attempt last year to climb the Mount Everest. Fate had other plans. Thwarted by unfavourable weather at the last minute, he came so close and yet not close enough to say he was at the top. But that did not deter him. Vikas is back on the Everest trail now, and this time he’s sharing his experiences at every leg of the journey.

The Everest journey began from the Lukla airport, known for its dicey landing conditions. It reminded him of the failed expedition, but he still moved on to Namche Bazaar - the staging point for Everest expeditions - with a positive mind. Vikas let the wisdom of the mountains guide him as he battled doubt and memories of the previous expedition. In his words, the Everest taught him that, “To conquer our personal Everest, we need to drop all our unnecessary baggage, be it physical or mental or even emotional”.

Vikas used a ‘descent for ascent’ approach to acclimatise. In this approach, mountaineers gain altitude during the day, but descend to catch some sleep. Acclimatising to such high altitudes is crucial as the lack of adequate oxygen can cause dizziness, nausea, headache and even muscle death. As Vikas prepared to scale the riskiest part of the climb - the unstable and continuously melting Khumbhu ice fall - he pondered over his journey so far.

His brother’s diagnosis of a heart condition in his youth was a wakeup call for the rather sedentary Vikas, and that is when he started focusing on his health more. For the first time in his life, he began to appreciate the power of nutrition and experimented with different diets and supplements for their health benefits. His quest for better health also motivated him to take up hiking, marathon running, squash and, eventually, a summit of the Everest.

Back in the Himalayas, after a string of sleepless nights, Vikas and his team ascended to Camp 2 (6,500m) as planned, and then descended to Base Camp for the basic luxuries - hot shower, hot lunch and essential supplements. Back up at Camp 2, the weather played spoiler again as a jet stream - a fast-flowing, narrow air current - moved right over the mountain. Wisdom from the mountains helped Vikas maintain perspective as they were required to descend 15km to Pheriche Valley. He accepted that “strength lies not merely in chasing the big dream, but also in...accepting that things could go wrong.”

At Camp 4 (8,000m), famously known as the death zone, Vikas caught a clear glimpse of the summit – his dream standing rather tall in front of him.

It was the 18th of May 2018 and Vikas finally reached the top. The top of his Everest…the top of Mount Everest!

Watch the video below to see actual moments from Vikas’ climb.

Play

Vikas credits his strength to dedication, exercise and a healthy diet. He credits dietary supplements for helping him sustain himself in the inhuman conditions on Mount Everest. On heights like these where the oxygen supply drops to 1/3rd the levels on the ground, the body requires 3 times the regular blood volume to pump the requisite amount of oxygen. He, thus, doesn’t embark on an expedition without double checking his supplements and uses Livogen as an aid to maintain adequate amounts of iron in his blood.

Livogen is proud to have supported Vikas Dimri on his ambitious quest and salutes his spirit. To read more about the benefits of iron, see here. To read Vikas Dimri’s account of his expedition, click here.

This article was produced by the Scroll marketing team on behalf of Livogen and not by the Scroll editorial team.