Are we really getting smarter?
We are, at least in terms of intelligence quotient, or IQ, which is the most broadly used measure of mental ability. Over the past hundred years or so, raw scores on IQ tests have improved steadily. The phenomenon is known as the Flynn effect, after political scientist James Flynn, who discovered it in the 1980s. According to his extensive research, IQ test scores in the U.S. increased by an average of three points per decade during the 20th century. IQs themselves have not risen, since the scoring of each new test version is calibrated to assure a mean score of 100, defined as average intelligence. But if measured on an unadjusted scale, the current generation would have IQs more than 20 points above those of their grandparents­ — or enough to distinguish a "dull normal" from a "bright normal." The shift is by no means exclusive to the U.S.: Many European countries, as well as Canada, Japan, Israel, China, Australia, and New Zealand, also recorded strong increases in IQ scores over the last century.

Why have IQ scores risen so consistently?
No one knows exactly, but there are many theories. Improved nutrition and medical breakthroughs in the 20th century enabled children in advanced nations to develop more quickly, enhancing their brainpower. Psychologists also point to a rise in educational standards during that time. As society's inequalities evened out, children at the low end, or "left tail" of the intelligence curve, were less likely to be left behind, contributing to a general rise in intellect. If that's true, however, the Flynn effect should now be weakening, since the vast majority of children in the Western world have access to schools, medical care, and adequate food.

Is that happening?
There is some evidence that IQ scores have stopped rising in Scandinavia, but a major new study has concluded that the Flynn effect is still going strong in the U.S. Researchers at Duke University examined IQ tests of more than 1.7 million American 5th, 6th, and 7th graders between 1981 and 2010, and established that the scores were still rising as steeply as ever. The study also found proof, for the first time, that the Flynn effect is not merely a result of formerly deprived children improving and bringing up the average score. The IQ scores of the brightest 5 percent of children — or the "right tail" of the intelligence curve — were shown to be rising, too. "The 'smart' are getting increasingly smarter," said Duke researcher Jonathan Wai.

Why would that be?
Environmental stimulation might play a part, Wai and his team suggest. Most 21st-century adolescents engage every day in problem solving similar to that encountered on IQ tests — whether it's puzzling over increasingly complex video games or watching TV shows with labyrinthine subplots and large casts of characters. "Because people are now forced to make sense of Lost or the Harry Potter series or World of Warcraft," says Jonah Lehrer, an author of books on psychology, "they're also better able to handle hard logic puzzles." Some scholars also point to a "social multiplier effect'' — the phenomenon that smart people who hang around with other smart people tend, as a group, to get even smarter.

Do IQ tests reliably measure 'smartness'?
That's a hotly debated question. IQ tests gauge abstract intelligence — the ability to solve logic problems — rather than verbal reasoning, mathematical skills, literacy, or creativity. Harvard psychologist Howard Gardner, among others, has argued that linguistic, musical, physical, and personal skills all ought to factor into any assessment of intelligence. Flynn himself has said that IQ really reflects the extent to which a person has adopted a scientific rather than a concrete or utilitarian worldview. "If you asked a person in 1900 what a dog and rabbit had in common, they would say you could use a dog to hunt rabbits," he said. "Today you would say they both are mammals." The second answer is worth two points on standard IQ tests; the first, though hardly an invalid response, yields zero points.

Do we profit from rising IQs?
Individually, yes; more broadly, not necessarily. The American Psychological Association has found that high IQ scores correlate with both high grades at school and good job performance. Flynn has noted that people with high IQs are lateral thinkers prone to "solving business problems on [their] feet rather than running to the boss for help." Linda Gottfredson of the University of Delaware argues, however, that pure intelligence "is a useful tool, but not a virtue." It helps people get ahead, she says, but has little connection with emotional well-being or conscientiousness. In other words, people today might be better problem solvers on paper than previous generations. But that doesn't mean they'll be willing to do what's necessary to, say, solve the problems of the U.S. economy.

The decline of thinking outside the box
While IQ scores are indisputably on the rise, American creativity levels are bottoming out. Analysis of the results of the Torrance Tests of Creative Thinking suggests that the creative abilities of American children have been spiraling downward for almost 20 years. The Torrance tests analyze young children's ability to come up with original ideas and put them into practice. Kyung Hee Kim, an assistant professor at the College of William & Mary School of Education, found that scores on Torrance tests taken by children up to 6th grade between 1968 and 2008 showed a steady decline after 1990. That's a serious issue at a time when creative thinking is among the most desperately needed skills in the American workplace. A recent study found that 85 percent of employers concerned with hiring creative people say they can't find the right applicants. Kim blamed America's standards-obsessed schools for creating an environment in which creative thinking was not nurtured. "Creative students cannot breathe, they are suffocated in school," she said. "Then they become underachievers."