Our brains are brilliant instruments, able to reason, synthesise, remember and imagine at an extraordinary pitch and rate. We trust them immediately and innately – and have reasons to be deeply proud of them too. However, these brains – let’s call them walnuts in honour of their appearance – are also very subtly and dangerously flawed machines. Flawed in ways that typically don’t announce themselves to us and therefore give us few clues as to how on guard we should be about our mental processes. Most of the walnut’s flaws can be attributed to the way the instrument evolved over millions of years. It emerged to deal with threats; some of which are no longer with us, and at the same time, it had no chance to develop adequate responses to a myriad of challenges generated by our own complex societies. We should feel pity for its situation and compassion for ourselves. Attempting to live requires us to adopt a focused and ongoing scepticism towards a great many of the ideas, schemes and feelings generated by the faulty walnut that stands at the top of our spinal column. Here are just some of the many things we need to watch out for: > The walnut is influenced by the body to an extent it doesn’t recognise: The walnut is extremely bad at understanding why it is having certain thoughts and ideas. It tends always to attribute them to rational, objective conditions out in the world, rather than seeing that they might be stemming from the impact of the body upon its thought processes. The walnut doesn’t typically notice the role that levels of sleep, sugar, hormones and other physiological factors play upon the formation of ideas. The walnut adheres to a psychological intepretation of plans and positions that are, at heart, frequently merely bodily. Therefore, the walnut can feel certain that the right answer is to divorce or leave the job right now rather than go back to bed or eat something to raise blood sugar levels. > The Walnut is influenced by its past, but can’t see its own projections: The walnut believes it is judging each new situation on its own merits, but it is inevitably drawing upon patterns of action and feeling shaped in previous years. This saves time, and has real evolutionary advantages, except that many situations in the present are in fact deceptive, resembling the past only sufficiently to trigger a familiar response, while in fact having many unique characteristics that get overlooked. At moments of ambiguity, the walnut can jump to some catastrophic conclusions. > The Walnut doesn’t like to stop and think: The walnut evolved for rapid, instinctive decision-making — and has a grievously hard time stepping back to address what we might term the big first order questions. So bad is the walnut at thinking, it often needs another walnut nearby to help it along its way. Thinking generates anxiety and a desire to run fast in the opposite direction because of the difficult truths the walnut might unearth. But in the presence of another walnut, we can’t so easily bolt and turn back to the web. That’s why philosophy started as a conversation and psychoanalysis depends on two people unpacking one person’s thoughts and associations. Sadly, we rarely call on other walnuts to help us to think and usually pass the time with walnuts chatting idly about sport or the latest celebrity scandal. > The walnut is bad at self-control and gets passionate about, and scared of the wrong things: The walnut constantly gets excited about things which aren’t good for it: sugar, salt, and sex with strangers for a start the list. Advertising knows how to exploit this cognitive frailty to perfection. Our confusions can generally be traced back to targets that would once have been crucial and fitting for us to focus on. Our desires used to be reliable in simpler environments, but in the complicated conditions of modernity, they cause chaos. The same holds true for our fears: in the past, fears were simply bound to things that could kill us. Fears were a good idea to get us out of genuine dangers. But nowadays, many things excite our fear systems without there being any real threat. We have panic attacks before speaking in public for no good reason while at the same time, the real, more subtle threats of modern life (global warming or another subprime mortgage financial crisis) evade our detection radars entirely. > The walnut is egocentric, not polycentric: The walnut is primed to look at things from its own point of view. It often simply can’t believe that there are other ways of considering an issue. Other people can therefore seem perverse, or horrible to it – sparking outrage or self-pity. It’s only in the last second, from an evolutionary point of view, that the walnut has started to try to imagine what it might be like to be someone else (a symptom of this is that it’s learnt to take pleasure in novels). But this is still a fragile empathetic capacity, which tends to collapse, especially when the walnut is tired, and someone is trying to persuade it of a strange-sounding idea. > The walnut isn’t an independent thinker: The walnut grew up dependent for its survival on the mood of the group or clan. It’s therefore highly primed to fit in with common sense and prevailing opinion. It doesn’t generally like to use itself as a source of original data or insight. Other people’s opinions matter hugely irrespective of how foolish they might be – or indeed widespread. Because we came from small groups, one or two compliments can delight us; one criticism can sow panic. This is tricky in the age of Twitter. > The walnut misunderstands causality: The walnut used to think it might have been responsible for the lightning in the sky and that earthquakes were a result of its own bad thoughts and deeds. It took a while for that skewed perspective to be overcome. But the walnut so constantly projects personal dynamics and overproduces generalities based on things that have happened to it: the walnut is trapped by personal rather than statistical or objective experience. Being more vigilant about the flaws in our walnuts gives us a range of important advantages: We can get better at noticing the potential errors in our judgments and ideas. We start to avoid mistakes when we know mistakes are a constant active possibility. Then, when we deal with other people, we can start to ask ourselves whether they might be acting from a walnut flaw, but not be aware of this. This can make us both bolder about disagreeing with them and also kinder and more generous in the face of their less than sensible behaviours. And then, when we deal with large groups of people, we can be aware that the walnut does very weird things in packs but that’s OK and no reason to panic if we find our ideas are meeting with resistance. At heart, compensating for the faulty equipment that nature has given us is the task of what we call: education, culture and civilisation. The flaws in the walnut are also what makes it imperative that we try to act with kindness and tolerance: we should at all times go easy on ourselves and others, for we’re trying to do some very difficult things around one another, with the use of a highly troublesome and only intermittently accurate tool.