"Individual humans know embarrassingly little about the world, and as history progressed, they came to know less and less. A hunter-gatherer in the Stone Age knew how to make her own clothes, how to start a fire, how to hunt rabbits and how to escape lions. We think we know far more today, but as individuals, we actually know far less. We rely on the expertise of others for almost all our needs. In one humbling experiment, people were asked to evaluate how well they understood the workings of an ordinary zip. Most people confidently replied that they understood them very well – after all, they use zips all the time. They were then asked to describe in as much detail as possible all the steps involved in the zip’s operation. Most had no idea. This is what Steven Sloman and Philip Fernbach have termed ‘the knowledge illusion’. We think we know a lot, even though individually we know very little, because we treat knowledge in the minds of others as if it were our own.
This is not necessarily bad. Our reliance on groupthink has made us masters of the world, and the knowledge illusion enables us to go through life without being caught in an impossible effort to understand everything ourselves. From an evolutionary perspective, trusting in the knowledge of others has worked extremely well for Homo sapiens.
Yet like many other human traits that made sense in past ages but cause trouble in the modern age, the knowledge illusion has its downside. The world is becoming ever more complex, and people fail to realise just how ignorant they are of what’s going on. Consequently some who know next to nothing about meteorology or biology nevertheless propose policies regarding climate change and genetically modified crops, while others hold extremely strong views about what should be done in Iraq or Ukraine without being able to locate these countries on a map. People rarely appreciate their ignorance, because they lock themselves inside an echo chamber of likeminded friends and self-confirming newsfeeds, where their beliefs are constantly reinforced and seldom challenged."
Yuval Noah Harari