New research is providing an answer to the age-old, delicate question: who is smarter, men or women? A new study has come down on the feminine side of that argument, finding that women now score higher on IQ tests than men.

The author of the study, James Flynn, a New Zealand-based researcher known as an IQ testing expert, said that over the past century, women have lagged slightly behind men in IQ testing scores, at times by as much as five points. But now, Flynn said women have closed the gap and even inched ahead in this battle of the intelligent sexes.

"Over the last 100 years, everyone in the developing world has been gaining about three IQ points, but women have been gaining faster," Flynn told ABC News. "This is the result of modernity. In every country where women have an equal chance of modernity, women have caught men [in IQ testing]."

Flynn has not yet published the results of his study, saving that for a book he will publish in September. But he told ABC News that he collected data from Australia, New Zealand, South Africa, Estonia and Argentina on scores on a standard IQ test, called the Raven test. Each country tested at least 500 men and 500 women, most between the ages of 15 and 18, Flynn said.

"In all of those samples, women are the equal of men, perhaps scoring a half point or a point higher," Flynn said.

The changes, Flynn said, can be explained by changes in opportunity and education that have come about in the last century - for example, less reliance on rote memorization in education and an emphasis on improving logic and analytic skills.

"As we enter the modern worlds, our minds change just as our automobiles have changed," Flynn said. "Where women can have an equal chance to interface with the modern world, they equal on IQ and surpass on academic performance."

He said there is no reason those advantages shouldn't go on to help women in the occupational and professional sphere, though there are other social factors affecting women's success in those arenas.

Deciding which is the smarter sex is an ever-controversial topic of conversation and scientific research. Studies of animals and humans have found definite differences between males and females, in things like brain size, verbal and spatial abilities and brain disorders, such as depression and schizophrenia. It's mostly unclear, though, how those differences translate to behavior.