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07 May 2009 06:00
When I was seven or eight, I found a wart growing on my knee. Sounds grim, I know, but bear with me.
Someone—an adult, nogal, so it had to be reputable, right?—told me that if you cut a raw potato in half, rubbed it on the wart and buried the potato, the wart would disappear.
I was methodical, though, and followed the instructions precisely. The weeping face of the half-potato was rubbed against the offending growth, a small tear hacked through the matted kikuyu grass in the back garden and the potato duly buried.
Would you believe it, that wart disappeared. I can’t remember if it took weeks, or months, but one day I peered down and discovered that my knee was wart-free.
In my mind: wart + spud + burial of said tuber = wart eradication.
What I didn’t know at the time was how typical this way of thinking is for the human brain. It’s got something to do with how we evolved in a perilous world and the ability of our brains to see patterns—to find links between cause and effect—determined whether we survived and passed on our genes.
If you see a “true” pattern (that log in the river looks like a croc, and is a croc, if you wade across the river you might die, so you don’t cross the river), you live. If you see a “false” pattern (that log in the river looks like a croc, so you decide not to wade across the river, but it turns out the log is just a log), you also live. So we’ve evolved to have the pattern-recognition software in our brains, even if it sometimes leads us to false conclusions.
Take the following example, brought up at a recent Southern African Science Journalists’ Association gathering. During a bad drought, a community in the Eastern Cape walks up a mountain to pray for rain. And it rains. In the mind of the narrator, this is evidence that praying for rain works.
To test whether prayer works to bring on the rains, you’d have to conduct an experiment: send the same community up the mountain on, say, the first Saturday of every month, without fail, for four years. Then you work out how many times it did rain, how many times it didn’t, and compare this with when it is statistically likely to rain because of the seasons. Only then could you have some kind of a meaningful statement on whether the prayer brought on the rain.
Ok, fine, so this is how Western science works.
“What about African science?” a Malawian scientist put to the group. “Say, a healer claims he has a treatment for Aids?”
This is a common misconception about science—that it’s a Western construct. And viewing it as such adds a whole lot of cultural baggage. The scientific method is not exclusive to the West, or exclusionary of different cultural “beliefs”. It’s a universal way of testing ideas about how the world works.
It’s like baking a cake. You take set ingredients, mix them together in a specific way and bake them at 180°C. It doesn’t matter whether you do that in New York, Beijing, Accra, Reykjavik or Kinshasa—if you follow that method, you will get a cake.
To test the healer’s claims, you’d have to subject those claims to specific methods of testing to try to eliminate anything that might skew the results (patients’ response owing to the placebo effect, other medical or nutritional pressures, age and general state of health).
I was relieved to read an extract from Kanya Ndaki’s essay in The Virus, Vitamins & Vegetables: the South African HIV/Aids Mystery recently. The gist of it: it’s not un-African or racist to challenge the claims of a healer who says his Aids cure was handed down to him by the ancestors. Subjecting claims such as this to empirical scientific testing is not a rejection of traditional culture, it’s about demanding that someone in a position of power in a community shows evidence for his claims lest he swindle desperate people out of money or away from legitimate treatments.
In hindsight, the mystery of the disappearing wart on my knee could be explained by a number of things: maybe an enzyme in the potato killed it; or it was ripped off in a playground tumble; or maybe it went away on its own? Either way, finding the answer is not always as easy as a + b = c, even though our brains are pre-programmed to reach that conclusion.
“Anecdotal thinking comes naturally,” says Dr Michael Shermer, publisher of Skeptic magazine, “science requires training.”
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