First, watch this:
Okay, if you were unwilling or unable to watch the video, here’s the executive summary. Gates notes that over 2 billion people have no access to fresh drinking water, and then introduces technology that produces pure, pathogen free drinking water from sewage sludge – human waste. The device also generates electricity as a bonus. At the end of the video, Gates fills a cup from the device’s output pipes and takes a swig.
This situation is rather close – though even more revolting – than a question I often ask my students when testing their propensity to magical thinking. It is this. Imagine you are on a long spaceflight, and NASA has equipped your spaceship with a recycling system that converts urine into drinking water. Would you feel comfortable drinking the water, assuming that the testing of the water confirmed its purity? This is similar to famous psychology experiments by Paul Rozin and colleagues on disgust. They found that people refused to drink liquid which they had seen the psychologist dip a dead cockroach in – even though they were told that the cockroach had been completely sterilized prior to the procedure.
Not surprisingly, many people are reluctant to drink recycled water. And yet, if you think about it (and most people don’t want to think about it!) – all our water is recycled. Trace that bottle of Evian back. Before it went into the bottle, it was presumably filtered and treated. Before that, it was presumably pulled from an aquifer, subjected to natural filtration. But before that? Was it rainwater running across an oily highway? Was it urine, squirted from a passing hawk? Was it the soapy, grungy water someone had used to wash their tires with?
Whatever it was before is rather irrelevant if it’s pure water now (or at least pathogen-free, toxin-free water). Whether it was purified by a natural aquifer or a water treatment facility or Bill Gates’s sludge machine or NASA’s space toilet, it can carry no memory if its previous life and no taint either. It is reasonable and normal for humans to have a disgust reaction to such things – disgust evolved to help us avoid truly dangerous situations – but it is unreasonable to let that initial reaction once proven unfounded to stop you from taking a long spaceflight. Or stop you from saving the lives of 2 billion people.
What gets in the way – and what could get in the way of Bill Gates’ device – is human propensity for magical thinking. Magical thinking has two components. First is the magical law of contagion. This is the idea that two things which were once in contact with one another maintain an effect on one another, even after the passage of time and even after the two items are no longer in contact. Thus, Rozin’s beverage seems permanently tainted by its association with a cockroach. The astronaut’s drinking water seems permanently tainted by its association with the astronaut’s toilet. The law of contagion underlies part of people’s resistance to eating genetically modified food or foods prepared in a microwave oven.
The second idea is the law of similarity, in which people generalize from a surface resemblance of two items to a deeper similarity. When reminded that all water is recycled, people become aware of the similarity of water and urine, ignoring the important differences that demand the two substances be treated in completely different fashion. This law of similarity underlies the hideous black market for rhinoceros horn, on the basis that the horn’s resemblance to a certain other body part indicates that it is a natural Viagra. It also underlies campaigns against food companies on the basis of food components that happen to be shared by non-food items, such as Vani Hari’s despicable campaign to pressure Subway to alter its bread formulations because both its bread and yoga mats and tennis shoes contain azodicarbonamide. Tell people their bread contains azodicarbonamide, and they’ll probably pause briefly before tucking in for another bite. Tickle their propensity to magical thinking by saying they are eating a yoga mat for lunch, and they’ll produce an impressive spit-take.
Disgust is an evolved defense mechanism, and so is magical thinking. They are part of the human experience. I know I would drink Rozin’s cockroach-tainted beverage, but I would do it out of a stubborn sense of defiance. Under other circumstances I would select another drink. That’s just who we are. But it gets serious when 2 billion people don’t have access to clean drinking water. It gets serious when a projected future world population of 10 billion will require genetically modified crops and modern agricultural practices in order for everyone to get fed. It’s time to suppress our disgust and get on with the business of turning technology to beneficial ends. I’m not a religious person, but the appropriate phrasing here is God bless people like Bill Gates for putting reason over magical thinking and making this thing happen.