THE ESSENTIAL CHILD
Children’s essentialist thinking is amazing.17 Before they reach school age, they know that baby joeys raised by goats grow up into adult kangaroos, not adult goats. They know that apple seeds grown in flowerpots become apple trees, not flowers.18 They even know that a light-skinned baby switched at birth with a dark-skinned baby remains the original colour despite being raised by the new family.19 A leaf insect may look more like a leaf than an insect, but four-year-olds know it shares properties with other bugs, not with leaves.20 When they are slightly older, they understand that if an evil scientist takes a raccoon and performs an operation to turn it into a skunk by attaching a furry tail, painting a white line down its back, and putting a bag of foul-smelling stuff between its legs, it is still a raccoon even though it looks like Pepé Le Pew.21 Essential thinking allows children to understand that the leopard literally can’t change its spots. And no one needs to teach children this. It’s part of their intuitive biological understanding.
Children’s essentialism is truly surprising, as pre-schoolers can often be fooled by outward appearances.22 However, once they understand what can and can’t be changed by environment, they are committed essentialists who see core properties everywhere. They think that there is something inside that cannot be changed. They don’t know what it is, and they would be hard-pressed to describe it. When it comes to understanding living things, they really seem to grasp that there is something deep inside that makes animals and plants what they are. It’s a universal beliefs shared by different cultures, suggesting that essentialism is a natural way of viewing the world.
Although children and most adults can’t describe exactly what an essence is, they can tell you where it is, if only indirectly. In one study, children were told about an ancient block of ice that had different animals frozen in it.23 Scientists wanted to determine what the different animals were by doing tests on small samples taken from the things inside the block. Children were asked whether it made a difference where the sample was taken from. By ten years of age, children reasoned like adults that it did not matter where the sample was taken because whatever defines an animal is spread throughout the body. In contrast, four-year-olds, the youngest children in the study, insisted that the true identity of an animal is found in only one spot and not spread out. When questioned further, these children seemed to think that the correct spot to choose was from the centre of the body. What starts out as a very localized notion of essence in young children develops into a belief about something that spreads throughout the body, even though these children never mentioned scientific concepts such as DNA.
POLAR MICE AND FISHY POTATOES
Essential thinking is increasingly shaping our attitudes towards the modern world. For example, by the time the leaves on a potato plant start to wilt, the potatoes underground are already stunted in size as the plant tries to compensate for lack of water. What if the plant could tell you that it needs watering before the leaves begin to wilt? There is one such potato plant whose leaves start to glow fluorescent green when they require water. It can warn you in advance that it needs water before the underground potatoes shrivel. The plant can do this because a gene from a jellyfish has been inserted into its genetic makeup. It’s a genetically modified plant. When water levels reach the critical level, the gene in the plant’s physiology turns on the fluorescent response. A potato that can communicate its needs is truly remarkable – almost sociable. But would you eat such a fishy potato?24
Or what about a supermouse that can survive freezing temperatures? The Alaskan flounder produces a protein that effectively produces an antifreeze in its blood to enable it to survive in subfreezing waters. Last year mice were bred with this gene that protected them from hypothermia.25 What’s more, the mice passed this gene on to their babies, demonstrating the potential to create new species of animals that cross the traditional taxonomic boundaries. In other words, these supermice were genetic freaks.
Those biological boundaries that we use to chop up the world are increasingly open to breech by new genetic engineering. There are real concerns about this technology, as it is not easy to predict exactly what unforeseen negative consequences may arise from artificially combining genetic material that would not normally occur in nature. In the remake of the sci-fi classic The Fly, the scientist Seth Brundle builds a machine that decomposes the body down into its constituent DNA particles and transports them from one pod to another where they are reassembled.26 By chance during one of his early experiments, a common housefly enters the pod with Seth. At first he notices nothing when he re-emerges from the other pod, but over the course of the movie Seth is gradually transformed into a human fly hybrid, with all the disgusting dining habits that flies exhibit (and you know what I think about flies). In most people’s minds, genetic engineering has brought us to the point where Seth Brundle’s predicament is no longer a fanciful tale of the dangers of tinkering with nature.
It’s not the fact that we can do genetic manipulation that is so worrying. After all, from the very beginnings of farming and animal rearing, we have been manipulating genes through selected breeding. All modern dogs are descendants of a fifteen-thousand-year-old programme of selective breeding of wolves.27 The problem is that gene insertion rapidly bypasses natural selection. There is no time to evaluate combinations that could be harmful. The potential for unforeseen consequences arising from unconstrained combinations worries the experts.
Around the world, governments are anxiously weighing up the concerns raised by genetic engineering with the potential benefits of new solutions to problems. For example, stem cells are the juvenile cells in fetuses that have the potential to replace damaged cells in adults.28 Many people suffering from illnesses and diseases such as Alzheimer’s disease would benefit if stem cells could achieve this repair. Unfortunately, there are not enough spare human eggs available to conduct this research, and so one solution has been to create animal eggs containing almost entirely human DNA. The resultant embryo, however, would still contain a small proportion of the donor animal’s original genetic material. This hybrid human–animal embryo could in principle be a potential real Seth Brundle. In truth, these embryos would never be viable, but the prospect of animal–human hybrids is simply too unacceptable for most of us. In March 2008, the British government faced a crisis as the Catholic Church urged Catholic politicians to resign over the introduction of the Human Fertilization and Embryology Bill, which allowed research inserting human DNA into animal cells. Ethics used to be a rather sleepy academic division of moral philosophy where one could ponder life’s hypotheticals. Today, advances in genetic engineering have thrust ethics into the public spotlight, with the expectation that it will provide answers to this minefield of moral dilemma. Philosophers have never been busier. Your average member of the public has never taken courses in philosophy or genetics, but they can still be appalled by the prospect of combining species. This is because of essentialism. It’s the way we all chop up the living world into its different groups. We intuitively think that members of the same category share this invisible property that defines their group membership. For example, we think that all dogs have a ‘dogginess’ essence that makes them members of the canine family and that all cats have a ‘cattiness’ essence that separates them from dogs and makes them members of the feline fraternity. When we hear about scientists inserting genes of fish into mice and potatoes, we feel squeamish. It just does not seem right. It’s not natural.