Is human intelligence increasing?

A new APA book, tackles the tricky issue of race and intelligence as it addresses three hotly debated research questions.

In 'The Rising Curve: Long-Term Gains in IQ and Related Measures,' intelligence researchers examine the gap between black-white intelligence test scores and the dysgenic theory of intelligence?the idea that less intelligent people are reproducing more than intelligent people, thereby depressing the world?s average intelligence.

'I wanted to put the record straight on these issues,' says the book?s editor Ulric Neisser, PhD, of Cornell University. 'And what it leaves you with is some good news?the black-white gap appears to be closing and the dysgenic theory can be refuted.'

For example, in one chapter Robert M. Hauser, PhD, shows that over the past 20 years school achievement scores have increased rapidly for U.S. blacks while staying the same for whites, reducing the gap by as much as half. This trend appears to correlate with government programs designed to equalize education for all U.S. citizens, Hauser and other authors contend.

As for a dysgenic trend in intelligence, Neisser gave dysgenic theorist Richard Lynn, PhD, 'his best shot at proving his point.' The book then ends with chapters by Irwin Waldman, PhD, and Samuel Preston, PhD, that refute the dysgenic argument point by point.

The book also explores a trend little known outside the intelligence research community: Scores on intelligence tests have been steadily rising over the past century, a trend called the Flynn Effect after James Flynn, PhD, who officially documented it in 1984.

While the book acknowledges that no one knows why test scores are rising, Flynn argues in one chapter that environmental factors must be responsible for the trend. Other chapters discuss alternative explanations for the increase, such as the theory that better nutrition over the past century is feeding people?s intelligence and the idea that technology has improved people?s ability to master intelligence tests.

The book, which will be available next month, grew out of a 1996 conference on the Flynn Effect organized by Neisser and cofunded by the APA Science Directorate and Emory University.

To obtain copies, contact APA Books at (800) 374-2721; TDD/TTY: (202) 336-6123. Or visit the APA world wide web page at: http://www.apa. org/books/. Cost is $34.95 for members and $39.95 for nonmembers.