Stephen Hawking’s last fear was rise of the superhuman

A posthumous book of the physicist’s last writings carries a stark warning about our skill in manipulating DNA.

He died seven months ago, but this has not stopped Professor Stephen Hawking sparking controversy about a new race of “superhumans”.

In his final prediction, one of the world’s most celebrated scientists suggests that genetic engineering was likely to create a new species of superhuman that could destroy the rest of humanity.

Hawking, who died in March, left a collection of articles and essays on what he called “the big questions”, in preparation for a book that will be published on Tuesday. In Brief Answers to the Big Questions he suggests that wealthy people will soon be able to choose to edit their own and their children’s DNA to create superhumans with enhanced memory, disease resistance, intelligence and longevity.

“I am sure that during this century people will discover how to modify both intelligence and instincts such as aggression,” he wrote. “Laws will probably be passed against genetic engineering with humans. But some people won’t be able to resist the temptation to improve human characteristics, such as memory, resistance to disease and length of life.”

Such ideas will horrify some because of their superficial similarity to last century’s eugenics movement — the idea that humanity could be “improved” by encouraging people with supposedly superior characteristics to have more children, while discouraging or even sterilising those seen as inferior.

Yet Hawking was only suggesting breakthroughs in genetics will make it attractive for people to try to improve themselves, raising issues for “unimproved humans”. “Once such superhumans appear, there will be significant political problems with unimproved humans, who won’t be able to compete,” he wrote. “Presumably, they will die out, or become unimportant. Instead, there will be a race of self-designing beings who are improving at an ever-increasing rate.”

Hawking’s comments refer to techniques such as Crispr, a DNA-editing system that allows scientists to modify harmful genes or add new ones. Invented just six years ago, it is already in use worldwide. London’s Great Ormond Street Hospital for Children has used gene editing to treat children with an otherwise incurable form of leukaemia, but scientists doubt parents would risk using such techniques for fear the “enhancements” would have side effects.

Lord Rees, the astronomer royal, who was a friend of Hawking at Cambridge University but often disagreed with him, noted that a sperm bank in California offering only “elite” sperm, including from Nobel prize winners, closed due to lack of demand. “A sharp distinction exists between medical interventions that remove something harmful and deploying similar techniques to offer ‘enhancement’,” said Rees, whose own book, On the Future of Humanity, came out last month. “Most characteristics . . . are determined by an aggregate of many genes. Modification of the genome is a remote, risky and dubious project.”

Other scientists welcomed Hawking’s predictions as the best hope for saving Earth from destruction. “Humans have arguably reached a critical moment,” said Chris Rapley, professor of climate science at University College London. “We have moved beyond affecting the planet at the landscape scale to interfering with its very metabolism at the global scale. All the indications are that the limitations of our brains, both individually and collectively, leave us incapable of addressing the challenge. On this basis the future looks desperately gloomy.”

Brief Answers to the Big Questions (John Murray) is out on Tuesday, price £14.99

LEADING SCIENTISTS ON THE FUTURE OF HUMANITY

Professor Lord Martin Rees, astronomer royal

We should be mindful of an unprecedented kind of change that could emerge within a few decades. Human beings themselves — their mentality and their physique — may become malleable through the deployment of genetic modification and cyborg technologies.

This is a game-changer. When we admire the literature and artefacts that have survived from antiquity we feel an affinity, across a time gulf of thousands of years, with those ancient artists and their civilisations. But we can have zero confidence that the dominant intellects a few centuries hence will have any emotional resonance with us — even though they may have an algorithmic understanding of how we behaved.

The 21st century is special because it is the first in which humans may develop habitats beyond the Earth. The pioneer “settlers” on an alien world will need to adapt to a hostile environment — and they will be beyond the reach of terrestrial regulators.

These adventurers could spearhead the transition from organic to electronic intelligence. This new incarnation of “life”, not requiring a planetary surface or atmosphere, could spread far beyond our solar system.

Interstellar travel is not daunting to near-immortal electronic entities. If life is now unique to the Earth, this diaspora will be an event of cosmic significance.

Chris Rapley, professor of climate science, University College London 

Humans have arguably reached a critical moment in the evolution of life on Earth. Through the “great acceleration” of technology, economy and population over the last 50 years, we have become the dominant driving force within the Earth’s interconnected systems, and have moved beyond affecting the planet (usually destructively) at the landscape scale to begin interfering with its very metabolism at the global scale.

By upsetting the planetary energy balance while simultaneously trashing the biosphere, we are undermining our life-support system in a highly reckless manner. All the indications are that the limitations of our brains, both individually and collectively, leave us incapable of addressing the resulting challenge.

We need to galvanise rational collective action, but our propensity to short-termism, denial and division leave us unable to do so. Witness the lack of action on climate change, for example, and the growing retreat from rationalism. The latter is an predictable psychological reaction to the overwhelming torrent of confusing information and the rapid and unsettling social changes we are experiencing.

Access to more and more information is not helpful if much of it is false, if we lack the capacity critically to appraise it, and especially if we feel we lack agency to respond.

On this basis the future looks desperately gloomy. However, there’s a wild card that could come into play, and that is the emergence of a subset of “super” humans who either, through genetic modification or AI enhancement, have the capacity to think and act collectively and rationally, based on evidence, and who address the aim of achieving an inexhaustible harmony of human behaviour on our finite, biologically-serviced “spaceship”.

The demise of unaltered humans will then not only be inevitable, as they are displaced by the enhanced species, but necessary, to prevent their inflicting further irreversible planetary damage.