Did you know that the incidence of cancer in the United States
has been declining for nearly 20 years? That the spread of
pornography correlates with a decline in rape? That average IQs are
going up substantially all around the world? These are just some of
the truths that are well-known to the scholars who study those
subjects but generally come as a surprise to even the best-educated
among us.
As reason reflects on how the world has changed
since the magazine’s founding in May 1968, here are seven
surprising pieces of unalloyed good news.
Cancer Rates Are Going Down
A 2007 American Cancer Society poll found that seven out of 10
Americans believed that the risk of dying from cancer is going up.
In fact, not only have cancer death rates been declining steeply,
age-adjusted cancer incidence rates have been falling for
nearly two decades. That is, in nearly any age group, fewer
Americans are actually coming down with cancer.
Advances in modern medicine have increased the five-year
survival rates of cancer patients from 50 percent in the 1970s to
68 percent today. That much you might expect. More surprising is
that the incidence of cancer has been falling about 0.6 percent per
year since 1994. That may not sound like much, but as John Seffrin,
CEO of the American Cancer Society, explains, “in recent years,
about 100,000 people each year who would have died had cancer rates
not declined are living to celebrate another birthday.”
Why is cancer becoming more rare? Largely because fewer
Americans are smoking, more are having colonoscopies in which
polyps that might become cancerous are removed, and many women
stopped hormone replacement therapy in the early 2000s, all
behaviors that prevent the onset of cancer. Advances in genetic
screening for cancer risks will further reduce cancer incidence as
empowered patients take preventive actions like actress Angelina
Jolie’s double mastectomy, which reduced her lifetime risk of
heritable breast cancer from around 90 percent to 5 percent.
The news is not all good. Rising levels of obesity have
been associated with increases in cancers of the kidneys,
esophagus, pancreas, and elsewhere. But falling mortality and
incidence rates do indicate real progress in the War on Cancer.
More Porn, Less Rape
Over the past two decades, as pornography has become much more
easily accessible over the Internet, the rate of rape and sexual
assault has declined by about 60 percent, according to the
Department of Justice’s Bureau of Justice Statistics
(BJS).
The BJS conducts an annual National Crime Victimization survey
of more than 100,000 households, asking if anyone has been the
victim of various crimes in the past year. In 1995, the rape/sexual
assault rate was reported as 5 per 1,000 American women over age
12. In 2011, the rate had fallen to 1.8 rapes/sexual assaults per
1,000.
Meanwhile access to pornography has dramatically increased. “It
is a truth universally acknowledged, that a person in possession of
a fast Internet connection must be in want of some porn,” the
journalist Sebastian Anthony joked last year on the website
Extremetech. Dozens of porn platforms are among the top
500 sites in terms of traffic, according to Google’s Doubleclick Ad
Planner. The largest, Xvideos, draws 4.4 billion page views per
month—three times more than CNN or ESPN, and twice as many as
Reddit.
A comprehensive 2009 review in the journal Aggression and
Violent Behavior by the Texas A&M International University
psychologist Christopher Ferguson and the University of Texas at
San Antonio criminologist Richard Hartley concluded that easy
access to porn does not cause rape. “Considered together, the
available data about pornography consumption and rape rates in the
United States seem to rule out a causal relationship,” Ferguson and
Hartley wrote in their summary of the academic literature. “One
could even argue that the available research and self-reported and
official statistics might provide evidence for the reverse effect;
the increasing availability of pornography appears to be associated
with a decline in rape.”
The Clemson economist Todd Kendall, in a 2006 study supported by
the National Bureau of Economic Research, concluded that “Internet
access appears to be a substitute for rape; in particular,
the results suggest that a 10 percentage point increase in internet
access is associated with a decline in reported rape victimization
of around 7.3 percent.” Kendall found that “there is no
statistically significant relationship between internet access and
any individual FBI index crime (other than rape), including murder,
robbery, aggravated assault, robbery, larceny, and auto theft.”
Crime rates are plummeting all over, but it’s only rape that
appears to be pegged to online connectivity.
Longer Life Expectancy Stops Population
Growth
An exciting convergence between demography and evolutionary
theory is shedding considerable light on why people the world over
are having fewer children. It turns out that the longer people can
expect to live, the fewer children they have. In fact, if current
fertility trends continue, world population could well top out in
the middle of this century at between 8 and 9 billion, then begin
to decline.
A fascinating study by the University of Connecticut
anthropologists Nicola Bulled and Richard Sosis looks at life
expectancy and fertility rates in 193 countries. In the October
2010 issue of Human Nature, they report that “when life
expectancy is high, educational attainment is also high,
reproductive timing is delayed, and overall reproduction
reduced.”
The University of Michigan ecologist Bobbi Low and her
colleagues have found that once women can expect to live past age
60, they begin to have their first child later in life and have
fewer children overall. Longer life expectancy is also correlated
with more education for women.
Bulled and Sosis report a similar finding: Women who live in
countries where life expectancy is below 50 years bear an average
of 5.5 children. When life expectancy is between 50 and 60, they
bear an average of 4.8 children. The big drop occurs when they can
expect to live between 60 and 70 years, in which case women have
about 2.5 children on average. The decline continues if women
expect to live between 70 and 75 years to 2.2 children, and falls
to just 1.75 children if they can expect to live older than 75.
The United Nations World Population Prospects 2010 Revision
reported that world average life expectancy for women is now 70
years. Global average life expectancy in 1960 was 52 years and the
total fertility rate was about 5 children per woman. As life
expectancy keeps rising, average total fertility today has fallen
to a world average of 2.36 children per woman, just slightly above
the 2.1 replacement rate.
People Everywhere Are Getting Smarter
About half of Americans two generations ago would have been
diagnosed as mentally retarded based on today’s IQ tests.
In 1980, the New Zealand political scientist James Flynn
discovered that average IQs in many countries have been drifting
upward at about 3 points per decade over the past couple of
generations. In fact, the average has risen by an astonishing 15
points in the last 50 years in the United States. In other words, a
person with an average IQ of 100 today would score 115 on a 1950s
IQ test, and a person of average IQ today would have been in
approximately the top 15 percent of same-age scorers 50 years ago.
If the average American kid were to take the first Stanford-Binet
IQ test from 1932, she would score about 124 points today.
“This means that on an IQ test made in 1930 the average score of
the entire population would give an IQ between 120 and 130
according to the original standardization,” the Hungarian
technologist Kristóf Kovács explains. So “instead of 2 percent,
35–50 percent of the population would have an IQ above 130. And
vice versa; if the current standard was applied to people living in
1930, average IQ would be between 70 and 80, and instead of 2
percent, 35–50 percent would be diagnosed with mental
retardation.”
What accounts for this massive increase in IQ scores?
Researchers have suggested a panoply of causes, including better
nutrition, exposure to more mentally challenging media, and more
formal schooling, but my favorite is the reduced load of infectious
childhood diseases.
A fascinating study published in the June 2010 Proceedings
of the Royal Society by the University of New Mexico biologist
Christopher Eppig and his colleagues finds an intriguing
correlation between the average IQ of a country’s citizens and the
intensity with which they suffer from parasites and infectious
diseases. The authors note that the brains of newborns burn up 87
percent of infants’ metabolic energy; 5-year-old brains use 44
percent; and adult brains consume 25 percent of the body’s energy.
Mobilizing the immune system to fight off diseases and parasites is
very metabolically expensive, diverting nutrients and energy that
would otherwise be used to fuel the building and maintenance of the
human brain. If this analysis is substantially correct, then
promoting public health also promotes higher IQs.
The new study reports, “Infectious disease remains the most
powerful predictor of average national IQ when temperature,
distance from Africa, gross domestic product per capita and several
measures of education are controlled for. These findings suggest
that the Flynn effect may be caused in part by the decrease in the
intensity of infectious diseases as nations develop.”
The converse of this research should find a correlation between
higher average IQs and increasing allergy and asthma rates. Allergy
and asthma rates are hypothesized to be on the rise because
children’s immune systems, no longer challenged by infections, have
become oversensitive, attacking the bodies they are supposed to
protect. Myopia also correlates with higher IQ scores; U.S. myopia
rates in people ages 12 to 54 increased from 25 percent in 1971–72
to 41.6 percent in 1999–2004. But higher IQ correlates with better
health and longer lives, less propensity to commit crimes, and
higher income (although not greater than average personal
wealth).
Trade Creates Jobs and Makes People Richer
Benjamin Franklin once declared, “No country was ever ruined by
trade.” Franklin believed that the free exchange of products across
borders was good for everybody, “even seemingly the most
disadvantageous.” But in the 21st century, many voters and the
politicians they elect believe the opposite. Being open to trade,
people fear, allows rapacious corporations to “ship jobs
overseas.”
A March 2011 European Economic Review study
forthrightly asks the question: Does exposure to international
trade create or destroy jobs? The answer strongly backs Franklin’s
observation. “A 10 percent increase in total trade openness reduces
aggregate unemployment by about three quarters of one percentage
point,” the authors conclude. Simply put: Trade creates
jobs.
Trade openness is generally measured by adding together the
value of a country’s exports and imports, then dividing that sum by
total gross domestic product (GDP). In other words, the higher a
country’s volume of international trade, the higher its degree of
trade openness. So the U.S. GDP in 2010 was roughly $15 trillion in
2010; exports and imports combined totaled just over $4 trillion,
yielding a trade openness index figure of around 27 percent.
Why does free trade create more jobs? The European Economic
Review study suggests that freer trade boosts overall
productivity, enabling companies to hire more workers. Trade
enhances competition, which weeds out inefficient firms and allows
more productive ones to expand. As the average efficiency of firms
in a country increases, they can earn more revenues by boosting
production. And that leads to hiring additional workers.
Trade openness also improves the lives and livelihoods of women.
A 2012 study by two German economists, Niklas Potrafke of the
University of Munich and Heinrich Ursprung of Konstanz University,
examined the relationship: “Observing the progress of globalization
for almost one hundred developing countries at ten year intervals
starting in 1970, we find that economic and social globalization
exert a decidedly positive influence on the social institutions
that reduce female subjugation and promote gender equality.”
A 2005 study in World Development by the London School
of Economics economists Eric Neumayer and Indra De Soysa found that
“countries that are more open towards trade and/or have a higher
stock of foreign direct investment also have a lower incidence of
child labor.” Openness to trade also correlates with higher school
attendance rates. This finding suggests that legislation such as
the recent bill proposed by Sen. Tom Harkin (D-Iowa) restricting
imports made using child labor would actually backfire, forcing
kids to work at less secure and less well-paying jobs in the
informal sector.
Trade openness is additionally coupled with higher per capita
incomes. In 2009, economists Vlad Manole of the Conference Board in
New York and Mariana Spatareanu of Rutgers devised a trade
restriction index to probe the degree of trade protection in the
economies of 131 countries using data between 1990 and 2004. They
found that “a 1 percent decrease in trade restrictiveness leads to
an approximately 0.3 percent increase in income per capita.”
So why do people, especially politicians, believe that freer
trade increases unemployment, hurts women and children, and reduces
incomes? The 19th century French economist Frederic Bastiat
explained this sort of disheartening policy myopia in his brilliant
essay, “What is Seen and What is Not Seen.” People tend to focus on
the seen consequences of a policy, such as competition from trade
eliminating some jobs at relatively inefficient companies. And they
miss the unseen benefits, such as the new jobs that result from
increased average productivity.
The protectionist politics that follow from this misdiagnosis
mean that a few seen workers get to keep their jobs while a much
larger number of unseen jobs never get created in the first place.
Meanwhile, the same laws make other Americans worse off by forcing
them to spend more, because they are denied access to less
expensive imports.
Local Biodiversity Is Increasing
Ascension Island is about as isolated as a piece of land can
get, sitting in the Atlantic Ocean about midway between Africa and
South America. When the British claimed authority over the
uninhabited, barren hunk of stone in the early 19th century, it was
frequently likened to a “cinder” or a “ruinous heap of rocks.” The
new owners named Ascension’s central peak White Mountain, after the
color of the bare rocks of which it was composed.
In 1846, botanist John Hooker from the Royal Botanical Gardens
at Kew visited and decided to try transplanting a wide variety of
plants onto the island. A century and a half later, the result has
been an “accidental rainforest.” White Mountain, now renamed Green
Mountain, is covered with an extensive cloud forest consisting of
guava, banana, wild ginger, bamboo, the Chinese glory bower and
Madagascan periwinkle, Norfolk Island pine, and eucalyptus from
Australia. Because of the man-made micro-climate, what used to be a
desert island now features several permanent streams.
Ascension Island undercuts the conventional ecological wisdom
that tropical rainforests are supposed to take millions of years to
form. And what happened on Ascension has been happening all around
the world, as people have moved thousands of species from their
native habitats to new locales, increasing species richness.
Wherever human beings have gone in the past two centuries, we have
increased local and regional biodiversity.
Yet “the popular view [is] that diversity is decreasing at local
scales,” the Brown biologist Dov Sax and the University of
California–Santa Barbara biologist Steven Gaines report in a 2003
article for Trends in Ecology and Evolution. Sax and his
University of New Mexico colleague James Brown point out in a 2007
roundtable in Conservation that “North America presently
has more terrestrial bird and mammal species than when the first
Europeans arrived five centuries ago.”
While some introduced species do outcompete natives and
contribute to their extinction, that phenomenon is relatively rare.
On the whole, the actual number of species in any given area has
tended to increase. For example, New Zealand’s 2,000 native plant
species have been joined by 2,000 from elsewhere, doubling the
plant biodiversity of its islands. Meanwhile, only three species of
native plants have gone extinct. In California, an additional 1,000
new species of vascular plants have joined the 6,000 native species
in the Golden State, while just 40 species have gone extinct.
Similar increases in plant diversity can be seen around the
globe.
The species that have become extinct and are most in danger of
extinction are those that dwell in isolated habitats such as
oceanic islands or freshwater streams. In a 2008 article for the
Proceedings of the National Academy of Sciences, Sax and
Gaines note that thousands of oceanic bird species went extinct as
Polynesians spread across the Pacific bringing not only themselves
but hungry rats. Nevertheless, they point out, the overall species
richness of the plant life on Pacific islands has increased
considerably, and bird species richness has remained about the
same, since the number of extinctions has been balanced by a number
of new species moving in.
Mammalian and freshwater species richness has dramatically
increased on Pacific islands as well—it was much harder for animals
like rats, pigs, deer, lizards, frogs, catfish, and trout to
colonize islands on their own. In addition, while some freshwater
species in continental streams and lakes have gone extinct, most
now harbor more species than they did before. Hawaii is, for
example, home to more than 2,500 new species of invertebrates.
In many cases, the newcomers may actually benefit the natives.
In a 2010 review article in the Annual Review of Ecology,
Evolution, and Systematics, the Rutgers ecologist Joan
Ehrenfeld reported that rapidly accumulating evidence from many
introduced species of plants and animals shows that they improve
ecosystem functioning by increasing local biomass and speeding up
the recycling of nutrients and energy. For example, zebra mussels
are very effective filter feeders that have helped clear up the
polluted waters of the Great Lakes enough to permit native lake
grasses and other plants to flourish.
“Imagine that an alien scientist from outer space were to visit
both New Zealand and Great Britain,” write Sax and Gaines. “Would
this individual be able to distinguish which species are native and
exotic, and would it be able to demonstrate that invaders have
caused more damage or disruption to ecological processes than
natives?” The answer to both questions is no.
Markets Make People Nicer
In The Communist Manifesto, Karl Marx
thundered that the bourgeoisie and the markets that allow them to
prosper “left remaining no other nexus between man and man than
naked self-interest, than callous ‘cash payment.’ ” In other words,
markets destroy fellow-feeling, turning human beings into cold,
cruel calculators. But recent research on how 15 small-scale
societies play certain canonical economic games suggests that
simply isn’t so.
The societies investigated by the economists and anthropologists
organized as the MacArthur Foundation’s Norms and Preferences
Network ranged from hunter-gatherers to slash-and-burn
horticulturalists on five continents. To probe these societies’
attitudes toward sharing and fairness, the researchers had their
members play several games. One of these is called the Ultimatum
Game. In it, researchers provisionally allot a divisible pie ($10,
say) to one player. This player, the “proposer,” offers a portion
of the pie to the second subject, the “responder.” The responder,
who knows both the offer and the total amount of the pie, chooses
to either accept or reject the offer. If the responder accepts, he
or she gets the amount offered and the proposer gets the remainder.
If the responder rejects the offer, neither player receives
anything.
Rationally speaking, one might expect that the proposer would
offer as little as possible ($1, say) and that the responder would
never reject an offer because, after all, one dollar is better than
nothing. Yet in hundreds of experiments in nearly two dozen
countries, subjects rarely act in that purely self-interested way.
In modern societies, the most frequent amount offered by proposers
is 50 percent, and responders commonly reject offers under a third.
After examining a number of different explanations, most
researchers have concluded that those choices are based on the
players’ sense of what is fair. Since these experiments are usually
conducted using western undergraduates, the Preference Network
researchers wondered if the results would hold true across
societies.
The experimenters offered participants the equivalent of a day
or two’s wages in their societies. The researchers found that the
average offers from proposers ranged from a low of 26 percent to a
high of 58 percent and that the most frequent offers ranged from 15
percent to 50 percent. Some groups, such as the Machiguenga and
Quichua in South America and the Hadza in Africa, offered around 25
percent of the pie. The most frequent offer from the Machiguenga
proposers was 15 percent. Only one Machiguenga responder rejected
such a low offer.
Societies like the Machiguenga and Hadza, which deal with few
outsiders and are not economically dependent on people other than
close kin, turn out to be the stingiest players. The Orma in Africa
and the Achuar in South America, who are more integrated into
markets, tend to play more like the western undergraduates. “The
higher the degree of market integration and the higher the payoffs
of cooperation, the greater the level of prosociality found in
experimental games,” the researchers found.
Herbert Gintis, co-director of the Preference Network team,
speculates that markets bring strangers into contact on a regular
basis, encouraging people to develop more concern for others beyond
their family and immediate neighbors. Instead of parochialism,
being integrated into markets encourages a spirit of ecumenism.
“Extensive market interactions may accustom individuals to the idea
that interactions with strangers may be mutually beneficial,” the
researchers theorize. “By contrast, those who do not customarily
deal with strangers in mutually advantageous ways may be more
likely to treat anonymous interactions as hostile, threatening, or
occasions for opportunistic pursuit of self-interest.”
Markets teach participants the habits of cooperation, trust, and
fairness. Based on his research, Gintis argues that history traces
humanity’s ascent from tribal selfishness to more cosmopolitan
liberality. “Market societies give rise to more egalitarianism and
movements toward democracy, civil liberties, and civil rights,”
Gintis argues. “Market societies and democratic societies are
practically co-extensive.” And they are more generous too.