Humans are very stupid – but we're smart enough to know it

Neuroscience shows we're hard-wired for stupidity. Happily, we can change habits, and must do so if we are to survive

The wrong conclusion? The nobel laureate Daniel Kahneman has shown how our thinking lets us down. But we can behave differently. 

We are getting smarter, aren't we? Or perhaps not. In a speech at the London Library, the novelist Sebastian Faulks expressed dismay at the collapse of knowledge in young people; and in my own life I don't see much evidence of the improvement. Each morning starts with my dropping an egg into boiling water and neglecting to note the time, so I end up with a hard boiled or runny egg. The kettle steams up my glasses, if I have remembered to bring them down to read the newspapers. The toast burns two out of seven mornings and the fire alarm goes off maybe once a week. Instead of reading the article that is useful to me, my mind wanders off on one of its pointless excursions.

I am prisoner of idiotic and clumsy habits, the worst of which is the faith, renewed with each night's sleep, that I can time the egg by instinct. My life is full of ludicrous self-confidence; for example, that this article will take one hour, rather than four, to write; that the fuel in my petrol tank will expand according to my need; that butter will not make me fat and that trains and planes are flexible in their departure times.

This is fine because I am not running a government or a bank. But look at the collapse of HBOS, and you will realise that the same stupid habits and hopeless optimism filled the heads of Lord Stevenson, former chairman of the bank, James Crosby, its megalomaniac former chief executive and his successor Andy Hornby. They weren't merely rash and greedy; they were stupid, because they ignored one of their own experts, Paul Moore, who warned about the risks that led to a bailout of £20bn and their own richly deserved humiliation.

An organisation that succumbs to this kind of failure suffers from "functional stupidity", a syndrome that requires such individuals as Mr Moore, who was fired from his job and eventually testified about HBOS to parliament, to stifle their criticisms and go along with the groupthink of powerful individuals. The same functional stupidity gripped the Blair and Bush governments as they went to war with a country that was not conceivably involved in the 9/11 attacks, and the groups of climate-change deniers who, for self-serving reasons or personality-driven prejudice, determine that all the evidence of a warming planet is cooked up by fantasists.

We are dumb beyond words in making the connection between our behaviour and well-understood outcomes – the links between smoking and cancer, fatty foods and obesity, driving fast and death on the roads, impulse buying and going broke, gossipy tweets and losing friends and esteem. We know the likely results but we are convinced we can defy norms with impunity, while denying ourselves nothing but the truth.

The literature on our stupidity seems to expand by the day. Every book on neuroscience and the choices we make seems to underline the reality that we are not in control, that "the two biological bags of fluid" as David Eagleman describes our brain in his book Incognito, are hard-wired for stupidity, or at least the triumph of emotional over rational systems.

Jonathan Haidt's book The Righteous Mind, an exploration of the psychological reasons for political and religious divisions, denies the existence of the effective force for good and sensible outcomes that we call reason. "Anyone who values truth," he writes, "should stop worshipping reason" in the social context, because it evolved not to help us find the truth of a matter, but to aid "argument, persuasion and manipulation".

The scientific thinking does force us to come to terms with the limitations of the two sacks of fluid. Research by the Nobel laureate Daniel Kahneman in Thinking, Fast and Slow shows that we are given to all sorts of short cuts that lead us to the wrong conclusion. He divides the mind, like many others before him, into two systems – one that operates automatically and quickly, with little effort and no voluntary control; the other that allocates attention to mental tasks and requires a high degree of effort. System one frequently suggests solutions that are not always right, but have a ring of truth about them. Greater knowledge of the way we think is a good thing, yet the reductionism seems to ignore the dazzling chambers of the human mind, which produced the first art in Europe 30,000 years ago, the Antikythera mechanism, the world's first computer, 2,100 years ago and today performs extraordinary feats of reasoning about the nature of the subatomic world and space-time.

The human brain is one of the most awesome objects in the known universe and the evidence, despite everything, is that we are getting smarter. For a start, the number of highly intelligent people alive is far greater than at any time in human history. If we take population growth since the second world war, we can assume that number of gifted individuals has risen proportionately, from roughly 2 million to 6 million – which, incidentally, happens to be the estimated total human population of the world at the end of the last ice age. We live in a more complicated world, which undoubtedly requires the brain to make more connections at greater speed. And potentially we have unlimited access to the sum of the world's knowledge at our fingertips.

The last doesn't necessarily make us brighter, but nor does it make us dimmer. Faulks's speech suggested that our children's generation would "capture" and remember far less than ours and that this was a kind of catastrophe for civilisation. I don't know what evidence my old schoolfriend has, but it seems obvious that the function of memory is being partly outsourced to the internet – what's the problem with that? – and that the web generation is going to make great leaps of understanding because of the new connectedness of human imagination and endeavour. They are operating in interestingly new ways.

Research suggests global average IQ is rising, but how do we reconcile that with our persistent stupidity, unnecessary wars, damaging inequality and denial of probable catastrophe? What hope is there for humanity if the lazy, self-serving, toast-burning creature of system one cannot change?

The answer, surprisingly, comes from Tony Blair who said when he was being recommended an employee because of their high intelligence, "But does he have good judgment?" After shouting "And well he might", it's worth noting that for intelligence to exist, stupidity must be vanquished. That requires judgment, the presence of the other voice in the boardroom or in your head that identifies dumb solutions and customary stupidity. And the good news is that habit can be taught. It will have to be if we are to survive.