What happens when there is no leader? Starlings, bees, and ants manage just fine. In fact, they form staggeringly complicated societies–all without a Toscanini to conduct them into harmony. This hour of Radiolab, we ask how this happens.
We gaze down at the bottom-up logic of cities, Google, and even our very own brains with fire-flyologists, ant experts, neurologists, a mathematician, and an economist.
7 Billion: By 2045 global population is projected to reach nine billion. Can the planet take the strain?
After rising very slowly for millennia, the number was just starting to take off. A century and a half later, when another scientist reported the discovery of human egg cells, the world’s population had doubled to more than a billion. A century after that, around 1930, it had doubled again to two billion. The acceleration since then has been astounding. Before the 20th century, no human had lived through a doubling of the human population, but there are people alive today who have seen it triple. Sometime in late 2011, according to the UN Population Division, there will be seven billion of us.
With the population still growing by about 80 million each year, it’s hard not to be alarmed. Right now on Earth, water tables are falling, soil is eroding, glaciers are melting, and fish stocks are vanishing. Close to a billion people go hungry each day. Decades from now, there will likely be two billion more mouths to feed, mostly in poor countries. There will be billions more people wanting and deserving to boost themselves out of poverty. If they follow the path blazed by wealthy countries—clearing forests, burning coal and oil, freely scattering fertilizers and pesticides—they too will be stepping hard on the planet’s natural resources. How exactly is this going to work?
THE ANNUAL meeting of the Population Association of America (PAA) is one of the premier gatherings of the world’s demographers. Last April the global population explosion was not on the agenda. “The problem has become a bit passé,” Hervé Le Bras says. Demographers are generally confident that by the second half of this century we will be ending one unique era in history—the population explosion—and entering another, in which population will level out or even fall.
But will there be too many of us? At the PAA meeting, in the Dallas Hyatt Regency, I learned that the current population of the planet could fit into the state of Texas, if Texas were settled as densely as New York City. The comparison made me start thinking like Leeuwenhoek. If in 2045 there are nine billion people living on the six habitable continents, the world population density will be a little more than half that of France today. France is not usually considered a hellish place. Will the world be hellish then?
Some parts of it may well be; some parts of it are hellish today. There are now 21 cities with populations larger than ten million, and by 2050 there will be many more. Delhi adds hundreds of thousands of migrants each year, and those people arrive to find that “no plans have been made for water, sewage, or habitation,” says Shailaja Chandra. Dhaka in Bangladesh and Kinshasa in the Democratic Republic of the Congo are 40 times larger today than they were in 1950. Their slums are filled with desperately poor people who have fled worse poverty in the countryside.
Eight billion corresponds to the UN’s lowest projection for 2050. In that optimistic scenario, Bangladesh has a fertility rate of 1.35 in 2050, but it still has 25 million more people than it does today. Rwanda’s fertility rate also falls below the replacement level, but its population still rises to well over twice what it was before the genocide. If that’s the optimistic scenario, one might argue, the future is indeed bleak.
But one can also draw a different conclusion—that fixating on population numbers is not the best way to confront the future. People packed into slums need help, but the problem that needs solving is poverty and lack of infrastructure, not overpopulation. Giving every woman access to family planning services is a good idea—“the one strategy that can make the biggest difference to women’s lives,” Chandra calls it. But the most aggressive population control program imaginable will not save Bangladesh from sea level rise, Rwanda from another genocide, or all of us from our enormous environmental problems.
If the term “singularity” rings a bell, that may be because you’ve read the 2005 bestseller The Singularity Is Near. Its author, computer scientist and inventor Ray Kurzweil, confidently predicts intelligence will soon cross a profound threshold. The human brain will be dramatically enhanced with engineering. Artificial intelligence will take on a life of its own. If all goes well, Kurzweil predicts, we will ultimately fuse our minds with this machine superintelligence and find a cybernetic immortality. What’s more, the Singularity is coming soon. Many of us alive today will be a part of it.
These failed predictions reveal a weakness at the heart of Kurzweil’s forecasts: scientific understanding doesn’t advance in lockstep with increases in technological horsepower. It was funny, in a morbid way, to watch Kurzweil make his case inside the 92nd Street Y just as a surge of swine-flu viruses was sweeping the city. There was a time when sequencing the entire genome of a single flu virus was a colossal, budget-busting project; now it costs a few hundred dollars. As of October 2009 the U.S. Influenza Genome Sequencing Project has collected the complete genomes of 4,087 viruses from around the world, and that number is rising close to exponentially.
Farah investigates how people try to enhance their cognition with drugs. Drugs originally designed to treat mental disorders are now being taken by perfectly healthy people. Adderall, a drug for ADhD, is a popular campus drug for boosting concentration. Modafinil, developed for people with narcolepsy, is now a drug of choice for those who want to burn the midnight oil.
In the years to come Farah anticipates even more powerful drugs will reach the market. Some are intended to slow the disappearance of memories in people with Alzheimer’s disease; others may boost cognition in people with impairments. Farah expects there will be people—maybe a lot of them—who will take these drugs in the hopes of improving an already healthy brain, not to fix a deficit.
First, scientists would have to decide exactly how much detail they’d need. Would they have to track every single molecule? Would a rough approximation of all 100 billion neurons suffice? Sandberg suspected scientists would need a scan of a brain that could provide details down to a few nanometers (less than a millionth of an inch). Today researchers at Texas A&M have figured out how to take images of the brain at a resolution of just 160 nanometers, but they’ve scanned only a rice-grain-size piece of mouse brain in any one trial. To scan the brain tissue the scientists must stain it with color-producing chemicals, dunk it in plastic for hardening and then shave away one layer at a time. For now brain emulation is a zero-sum game.
Before the effectiveness of a drug can be confirmed, it must be tested and tested again. Different scientists in different labs need to repeat the protocols and publish their results. The test of replicability, as it’s known, is the foundation of modern research. Replicability is how the community enforces itself. It’s a safeguard for the creep of subjectivity. Most of the time, scientists know what results they want, and that can influence the results they get. The premise of replicability is that the scientific community can correct for these flaws.
But now all sorts of well-established, multiply confirmed findings have started to look increasingly uncertain. It’s as if our facts were losing their truth: claims that have been enshrined in textbooks are suddenly unprovable. This phenomenon doesn’t yet have an official name, but it’s occurring across a wide range of fields, from psychology to ecology.
Although many scientific ideas generate conflicting results and suffer from falling effect sizes, they continue to get cited in the textbooks and drive standard medical practice. Why? Because these ideas seem true. Because they make sense. Because we can’t bear to let them go. And this is why the decline effect is so troubling. Not because it reveals the human fallibility of science, in which data are tweaked and beliefs shape perceptions. (Such shortcomings aren’t surprising, at least for scientists.) And not because it reveals that many of our most exciting theories are fleeting fads and will soon be rejected. (That idea has been around since Thomas Kuhn.) The decline effect is troubling because it reminds us how difficult it is to prove anything. We like to pretend that our experiments define the truth for us. But that’s often not the case. Just because an idea is true doesn’t mean it can be proved. And just because an idea can be proved doesn’t mean it’s true. When the experiments are done, we still have to choose what to believe.
Attachment theory designates three main styles or manners in which individuals perceive and respond to intimacy in romantic relationships, which parallel those found in children. Basically, secure people feel comfortable with intimacy and are usually warm and loving. Anxious people crave intimacy, are often preoccupied with their relationships and tend to worry about their partner’s ability to love them back. Avoidant people equate intimacy with a loss of independence and constantly try to minimize closeness.
Every person, whether he or she has just started dating someone or has been married for 40 years, falls into one of these categories—or, more rarely, into a combination of anxious and avoidant. Just more than 50 percent are estimated to be secure, around 20 percent are anxious, 25 percent are avoidant, and the remaining 3 to 5 percent fall into the mixed anxious/avoidant category. During the past two decades since Hazan and Shaver’s seminal paper on romantic adult attachment, hundreds of scientific studies in a wide range of countries and cultures have carefully delineated the ways in which adults behave in close romantic ties. Understanding these styles is an easy and reliable way to understand and predict people’s behavior in any romantic situation.