The early 21^st Century has been noteworthy for a marked increase in the number of governments willing to act against the interests of their electors – and the number of electors prepared to vote against their own best interests and choose such governments.

Since an educated, thoughtful and responsible electorate is indispensable to any democracy that wishes to choose a safe, rational and healthy future for itself it is fair to conclude that, if this trend persists, the 3-century-long worldwide democratic experiment will fail.

Whether the failure is attributable to large scale corruption of the democratic process by global corporates of rising wealth and power, to increased selfishness in politics and society or to rising stupidity on the part of C21st Homo sapiens both in politics and in the general community is still debatable.

In Earth Detox, a new book published by Cambridge University Press, I explore evidence for the latter hypothesis – that humans are, in fact, becoming progressively less intelligent. So dumb, in fact, that most do not grasp we are in mortal danger from ten vast, interconnected megathreats. Consequently, voters now frequently choose governments that either increase these threats – or which are too slothful or corrupt to abate them.

The missing piece of information is that all humanity is now engulfed, 24/7, in a flooding tide of toxic chemistry – a tide five or six times larger than our climate emissions, and more deadly that any previous threat to human existence. A threat that, according to WHO, kills over ten million people every year – the worst death toll from a single cause in human history. Why electors should vote for such an outcome for themselves and their children demands explanation.

One answer may be that our intelligence, the quality that humans have most prided themselves on down the ages, is in decline.

After a marked increase in human intelligence during the first three-quarters of the twentieth century – a phenomenon known as the Flynn Effect, after the NZ psychologist who discovered it – recent scientific research points to a clear downturn in human brainpower since 1975.

The average rate of decline has been around three IQ points a decade, amounting to the loss of about 13.5 per cent in average intelligence between 1975 and 2020. Results from separate studies carried out in seven different countries substantiate a widespread loss of intelligence.

So far, researchers have been unable to confidently assign a cause to this marked decline, saying only that it is not genetic and must therefore be due to something in society’s living environment. The big question is: what has changed so much in society’s living conditions as to cause such extensive brain damage during the past 45 years in particular?

Increasingly, science suspects the 350,000 man-made chemicals, many of them nerve poisons, which industrial society has unleashed on itself in this period and which now permeate our air, our food, our water, our homes, workplaces, our bodies and our genes every day. Substances to which virtually all humans are now exposed every second of their existence from conception to expiry and which are, for the most part, unavoidable. The impact of these nerve poisons is compounded by a second, related, chemical flood – the endocrine disruptors (EDCs), industrial chemicals which affect basic processes like our growth, development, gender, ability to reproduce, obesity and cancer risk.

Nerve poisons are now thought by medical scientists to play a significant role in the pandemic of brain diseases which have become more prevalent in recent decades – such as autism and ADHD, Alzheimer’s and Parkinson’s, depression and other mental disorders and the loss of intelligence. According to WHO, mental conditions now affect two billion human beings, one in every four, imposing a vast and growing cost on the world economy for care of the disabled.

Brain damage caused by nerve poisons has been known since ancient Rome and well understood by science for decades. Lead and mercury used to be the chief offenders, but in recent times they have been overtaken by certain pesticides and domestic chemicals, such as flame retardants. These are now found in the blood of unborn babies as well as much of the population.

A decline of seven IQ points translates the average citizen to the intelligence level of the average gaol inmate. It is therefore probable that the decline in human intelligence is being accompanied by an increase in rates of murder, rape and violent assault – as well as lack of foresight at the ballot box.

Proving that nerve poisons are responsible for the decline in democracy is no easier than proving cigarettes cause cancer – but the connections are now evident for all who care to look. William of Occam would note that human IQ is falling at the same time as the toxic load on society is redoubling – and we are witnessing tens of millions of voters without the ability to grasp their responsibility, the needs of their society and even themselves. Voters who may, on occasion, incoherently seek to overthrow or sabotage through misinformation the very system they do not comprehend.

Democracies have long asserted a moral as well as governmental superiority over autocracies, but with the decay in voter intelligence that advantage is becoming far less clear. If democracy is to endure as a form of self-governance, then the need to remedy the dumbing-down of democracy by ceasing to poison the minds that uphold it, is both imperative and urgent.

*Julian Cribb is an Australian science writer and author of Earth Detox: how and why we must clean up the Earth, UCP 2021. He is a founder of the Council for the Human Future.