A carnival of error

9 July 2013

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The Wrong! event at Wellcome Collection on Friday celebrated wrongness with a ‘carnival of human error’. Iona Twaddell learned that being wrong can be entertaining, and can actually sometimes be useful.

One obvious way in which we all enjoy being wrong is when we watch magic. I learned this as I came through the door and a close-up magician convinced me that my chosen queen of spades had magically appeared in his wallet. The reason we fall for these tricks was explained later by Dr Gustav Kuhn, who spoke about the psychology of magic. Our visual system has inherent limitations. We think we see a full picture of the world around us, but in actual fact we only ever see a tiny amount. This is partly because the world is only in focus on a small patch of the retina, known as the fovea. We use eye movements to focus important objects onto the fovea but the rest is blurry. And even when we are looking at something is in focus, we might not consciously see it, because seeing requires attention. This is why driving while using your mobile phone is so dangerous: you may see an obstacle in front of you, but if you’re not attending to it you won’t notice it. This is also why magic works. The magician uses misdirection to make sure you don’t attend to the trickery. But, as Dr Kuhn told us, being fooled by a magician actually shows us that our brain processes information efficiently, only seeing what is relevant. We’re wrong because our brains didn’t evolve to spot magicians’ tricks but to spot important visual information, like predators.

And I got more used to being wrong throughout the night. In the Medicine Man gallery I learned I knew nothing about obscure medical facts. Who knew that transplanting faecal matter from healthy intestines into unhealthy ones to cure bacterial disease was a current medical practice? I certainly didn’t. You can learn a lot from being wrong.

Not feeling too bad about being wrong about facts I had no reason to know, I learned that I was even wrong about my own body. Various illusions showed how you can trick your body into thinking it’s not your own. They can induce the feeling that your face is merged with someone else’s or make you feel like a fake hand is your own. Several of these illusions occur because our visual system overrides what we feel: we trust sight more than touch. These mistakes can actually help us sometimes: a mirror box is used for amputees with ‘phantom limbs’ (they feel that their amputated limb is still there) to make them feel like they ‘see’ their missing limb and hopefully get rid of any pain that might be lingering there.

Finally, I learned how irrational our choices are from Dr Benedetto de Martino. He told us that instead of being like Spock, making decisions by weighing up all possible evidence, we are more like Winnie the Pooh. Various phenomena show this. For example, McNeil and colleagues in 1988 asked expert doctors whether they would choose surgery as a treatment for cancer. The risk of surgery was either framed as survival rate or mortality rate. The experts were more likely to go for the risky surgery if the risk was framed as survival (a gain) than as mortality (a loss). This risk-seeking behaviour for gains and risk-averse behaviour for losses is also seen in gambling tasks in the lab and seems to be determined in a large part by the amygdala, a brain region important for emotion. Those without an amygdala tend to make the same choices regardless of how the question is framed. But being logical on these tasks might not actually be being truly rational. If you consider rationality being optimally adapted to the environment, then in fact we are very rational. Dr de Martino explains this by considering that in nature, a gain will often be small (getting some water) and you will have another chance to get the gain if you fail. But a loss could be death, with no second chance. So avoiding loss is more important than making a gain. Though we may be wrong from Spock’s view, we are right for our environment.

I hope I’ve given you an idea of carnival of human error on show. But actually what I’ve learned is that a lot of the time, it’s all right to be wrong.

Iona Twaddell is an Assistant Editor at the Wellcome Trust.