Sorry, who are you?
Prosopagnosia is a medical condition that stops people from recognising people’s faces. But how common is it and why does it happen?
It was Jacob Hodes’s first day at college. He recalls spending an enjoyable afternoon being shown around campus by a second-year student named Daniel Byrne, who happened to be from his home town. Jacob then spent the rest of the year ignoring him. “I never saw him again,” he says. “Well, I’m sure I walked past him plenty of times, but I just didn’t see him.” This behaviour wasn’t intentional. Jacob just couldn’t recollect what his fellow student looked like. He had had the same trouble all his life. Friends and relatives would greet him and he would have no idea who they were.
It wasn’t until five years ago that it all made sense. That was when Hodes was diagnosed with prosopagnosia, a condition that means he is unable to recognise faces. According to researchers, he is far from alone. In fact, the condition is not that uncommon, but until a few years ago, only a few dozen cases had ever been described, and all of these had been caused by brain injury. Recently, though, researchers identified a second form of face blindness: developmental prosopagnosia, which is either present from birth or develops very early in life.
In May, a team from Harvard University in the US and University College London (UCL) announced the results of a web survey of 1,600 people, suggesting that up to 2 per cent of people have some degree of face blindness. Then in August, Martina Grüter and colleagues at the Institute for Human Genetics in Münster, Germany, similarly reported that 2.5 per cent of 700 secondary school pupils they had tested had trouble recognising faces. The results of the surveys took everyone by surprise.
It seems that if you have never known what it is to recognise a face, you don’t necessarily know that you are supposed to be able to. “Prosopagnosics almost always know that they have trouble recognising people, but they often don’t realise that other people have better recognition skills than they do,” says Brad Duchaine, a researcher at UCL.
Despite these issues, the majority of developmental prosopagnosics possess strategies that allow them to get around their difficulty, for instance, by recognising hair, clothing or a person’s way of speaking. So, unless they see a familiar person out of context, with a new hairstyle or in different clothes, they can recognise people just fine. Even so, the discovery of developmental prosopagnosia has attracted attention from neuroscientists keen to discover what is different about the brains of face-blind people. This difference, they believe, could help solve the problem of how the brain deals with information in general, not just visual data. In other words, it may show whether the brain has specialised parts for specific tasks or is more of a general-purpose information processor.
One issue, however, that will present challenges for researchers is that no two prosopagnosics are the same. Some have problems only with faces, while others have trouble with ordinary everyday objects and, so it turns out, animals which would normally be familiar as well. Some prosopagnosics can train themselves to recognise specific faces; others can’t even recognise their own in a mirror. When some have been tested, they could identify the emotion which was conveyed on another’s face, even though the face itself seemed unfamiliar, while for other subjects this was an impossibility. Some cannot recognise the faces of old friends or fellow students but have no trouble telling whether a particular face from such groups would be attractive to most people. Because of this diversity, working out the cause of prosopagnosia will not be easy.
In Martina Grüter’s study, the prosopagnosics who agreed to have their parents and relatives tested reported at least one with the condition. Having looked at 38 cases in seven families, the German team believe they have good evidence that a single gene could be responsible. Duchaine also has some evidence that face blindness could be inherited but thinks other factors might be more significant. He refers to studies of babies born with a condition which means the eye’s lens is not clear, and when it’s the left one, being unable to see through this eye during the first two months of life is a major risk factor for prosopagnosia.
Whatever the cause, what most prosopagnosics want to know is whether they can do anything to improve their face-recognition skills. Joseph DeGutis, a graduate student at the University of California, recently reported successfully training a severe developmental prosopagnosic to recognise faces during tests carried out in the laboratory. The subject also reported that recognising faces in everyday life became easier due to the training. Duchaine now plans to attempt to train sufferers to recognise the five people that they most need to know, maybe their immediate family, for example, and essential colleagues.
Thomas Grüter, Martina Grüter’s husband, who also works on her team, however, is not convinced it will work. “I don’t know how you can have more training than you have already had,” he says. “Humans already spend all day looking at faces.” He also points out that cheating is a possibility during tests and provides an example. “One person we studied said that when she was doing the face-recognition test, she memorised the distance between nose and upper lip. She wasn’t the only one. So, you can perform well in the test and not do so well in real life.”
Understanding and Protecting Elephants
A The future of the African elephant is at risk. They are often shot by poachers for their ivory and this is responsible for most of the decline in elephant numbers. But habitat loss is important too, and not just the changing of bush into farmland. Roads, railways and fences stop elephants moving around, and an elephant needs a lot of room. According to George Wittemyer of Save the Elephants, an average elephant ranges over 1,500 square kilometres over a year and may travel as much as 60 kilometres a day.
B The question is whether elephants and people can ever coexist peacefully. People who worry that the answer may be ‘no’ fear the loss of more than just another species of animal. Elephants seem to have evolved intelligence, and possibly even consciousness. Though they may not be alone in this (similar claims are made for certain whales, some carnivores like lions and hyenas, and some birds), they are certainly part of a small group. Self-awareness is one indication of the vast capacity for thinking and intellect that exists in the elephant. They can, in fact, identify themselves in a mirror, something that is extremely rare in the animal kingdom. Another example of superior intellect is the elephant’s ability to have fun and display a sense of humour. Elephants in zoos have even been seen stealing onlookers’ caps and hiding them in playful teasing. Losing even one example of how intelligence develops would reduce the ability of biologists to understand the process of how intelligence has evolved in animals.
C Apart from people, no species on Earth has a more complex society than elephants. Their social arrangements centre around groups of four or five females and their young that are led by a matriarch who is mother, grandmother, great-grandmother, sister or aunt to most of them. Though males are forced to depart their birth group when they mature, females usually remain in it their entire lives. Elephant families are part of bigger ‘kinship’ groups that come together and separate at will. Moreover, each kinship group is part of what is called a clan. Clans gather in the dry season, when the resources capable of supporting elephants are limited. All clan members know each other and, since a clan will usually have 100 to 200 adult members, this means an adult female can recognise and have meaningful social relations with that many other individuals. A figure of between 100 and 200 acquaintances is similar to the number of people a human being can maintain meaningful social relationships with—a value known as Dunbar’s number. Dunbar’s number for people is about 150.
D Being able to recall details of such large numbers of individuals means elephants require enormous mental powers. Details of how their brains work are not known, but one thing which is known is that they have big hippocampuses. These structures, one in each hemisphere of the brain, are involved in the formation of long-term recall. Compared with the size of its brain, an elephant’s hippocampuses are about 40 per cent larger than those of a human being.
E Elephants can seemingly solve problems by thinking about them in abstract terms. Experiments conducted on domesticated Asian elephants show that they are able to manipulate nearby objects, such as branches, as tools to get food which is out of reach. This is something some other species, such as great apes, can do, but which most animals find impossible. For all of these reasons, then, elephants are of great scientific interest. But the focus of almost all elephant researchers has shifted from understanding the animals to trying to preserve them.
F Another, though secondary, cause of elephant decline is changes in land use in Africa. The human inhabitants of areas around African elephant reserves have traditionally survived by moving herds of cattle from one grazing place to another. One source of conflict with elephants has been competition for pasture, as the herders’ populations have grown. But, additionally, some herders have begun to settle down. Buildings and fences are appearing on land which elephants have traditionally crossed as they travel from one place to another. Elephants have places where they prefer to live and, when travelling between these, which they often do at night, they tend to follow narrow corridors. Keeping these corridors clear of development is essential to the well-being of elephants.
G Understanding elephants’ behaviour also permits it to be changed in ways that help reduce direct conflict between elephants and people. One such project uses elephants’ fear of bees. Bees are the only animals, apart from humans, that elephants seem truly afraid of. This is because, although a bee’s sting cannot penetrate most parts of an elephant’s hide, groups of bees tend to attack the eyes and the tips of the trunks, an elephant’s most sensitive parts. Elephants can’t protect themselves from the bees—not even by swinging their tails and flapping their ears.
H Knowing this, scientists developed the idea of protecting farms with bee fences. The sort of fence most African farmers can afford is too weak to keep an elephant away from their crops, but a bee fence, though even weaker, will achieve this. The fence consists of pairs of poles placed at three-metre intervals, between which beehives are hung. This fence is enough to stop elephants immediately. They are so scared that half the hives can be fake, and the fence still keeps the elephants out. Bee-fenced farms suffer far fewer elephant attacks than those with conventional protection. As a bonus, the farmers earn extra income from the honey the bees produce.
Let’s teach them how to teach
What matters in schools is teaching. Fortunately, teaching can be taught.
Forget smart uniforms and small classes. The secret to stellar grades and thriving students is teachers. One US study found that in a single year’s teaching the top 10% of teachers impart three times as much learning to their pupils as the worst 10% do. Another US study suggests that if black pupils were taught by the best quarter of teachers, the gap between their achievement and that of white pupils would disappear. But efforts to ensure that every teacher can teach are hindered by the persistent myth that good teachers are born, not made. Government policies, which often start from the same assumption, seek to raise teaching standards by attracting high-flying graduates to join the profession and prodding bad teachers to leave. Teachers’ unions, meanwhile, insist that if only their members were free from centralised policies, excellence would follow.
The premise that teaching ability is something you either have or don’t is mistaken. A new breed of teacher trainers is founding a rigorous science of pedagogy. The aim is to make ordinary teachers great, just as sports coaches help athletes of all abilities to improve their personal best. Done right, this will revolutionise schools and change lives.
Education has a history of lurching from one ‘miracle’ solution to the next. The best of them even do some good. The US initiative Teach for America has brought energetic new graduates into the profession, and dismissing teachers for bad performance has boosted results in Washington, DC. But each approach has its limits. Teaching is a mass profession: it cannot grab all the top graduates, year after year. When poor teachers are fired, new ones are needed—and they will have come through the same educational system that failed to make fine teachers of their predecessors.
By contrast, the idea of improving the average teacher could revolutionise the entire profession. Around the world, few of the newly qualified teachers are well enough prepared for the classroom. A recent report found 31 countries in which more than a quarter of primary school teachers had not reached minimal national standards. In rich countries, the problem is subtler. Teachers qualify following a long, specialised course. This will almost always involve superficial and apparently useless discussions of theory. Some of these courses, including master’s degrees in education, have no effect on how well their graduates’ pupils end up being taught.
What teachers fail to learn in universities and teacher-training colleges they rarely pick up on the job. They become better teachers in their first few years as they get to grips with real pupils in real classrooms, but after that improvements tail off. This is largely because schools neglect their most important pupils: teachers themselves. Across the Organisation for Economic Co-operation and Development (OECD), a club of mostly rich countries, two-fifths of teachers say they have never had a chance to learn by sitting in on another teacher’s lessons; nor have they been asked to give feedback on their peers.
If this is to change, teachers need to learn how to impart knowledge and prepare young minds to receive and retain it. Good teachers set clear goals, enforce high standards of behaviour and manage their lesson time wisely. They use tried-and-tested instructional techniques to ensure that all brains are working all the time, for example, asking questions in the classroom with cold calling rather than relying on the same eager pupils putting up their hands.
With teaching, like other complex skills, the route to mastery is not abstruse theory but intense, guided practice grounded in subject-matter knowledge and pedagogical methods. Trainees should spend more time in the classroom. The places where pupils do best—for example, Finland, Singapore and Shanghai—put novice teachers through a demanding apprenticeship. In the US, high-performing schools teach trainees in the classroom and bring them on with coaching and feedback.
Teacher-training institutions need to be more rigorous. A century ago, medical schools raised the calibre of doctors by introducing systematic curriculums and providing clinical experience. It is essential that teacher-training colleges start to collect and publish data on how their graduates perform in the classroom. Courses that produce teachers who go on to do little to improve their pupils’ learning should not receive subsidies or see their graduates become teachers. They would then have to improve to survive.
Big changes are needed in schools, too, to ensure that teachers improve throughout their careers. Teachers in the best ones hone their craft through observation and coaching. They accept critical feedback—which their unions should not resist but welcome, as is only proper for people doing such an important job. The best head teachers hold novices’ hands by helping them prepare high-quality lessons and arranging for more experienced teachers to cover for them when they need time for further study and practice.
Money is less important than you might think. Teachers in top-of-the-class Finland, for example, earn about the OECD average. But ensuring the best teachers stay in the classroom will, in most places, mean paying more. People who thrive in front of pupils should not have to become managers to earn a pay rise. And more flexibility on salaries would make it much easier to attract the best teachers to the worst schools.
Improving the quality of the average teacher would raise the profession’s prestige, setting up a virtuous cycle in which more talented graduates clamoured to join. But the biggest gains will come from preparing new teachers better, and upgrading the ones already in classrooms.
Cold calling: a simple technique in which the teacher calls on specific pupils to answer a question, regardless of whether they have raised their hand.