Excerpt from Why Gender Matters by Leonard Sax, plus links to reviews, author biography & more

After waiting a few years for somebody else to write a book about girls and boys based on actual scientific research, I finally decided to write one myself. But I made myself a promise. Every time I make any statement about how girls and boys are different, I will also state the evidence on which my statement is based. Every statement I make about sex differences will be supported by good science published in peer-reviewed journals.

There is more at stake here than the old question of nature versus nurture. The failure to recognize and respect sex differences in child development has done substantial harm over the past thirty years—such will be my claim throughout this book. Children today face challenges that are substantially different from those you faced as a child or teenager, fifteen or twenty or thirty or forty years ago. Look at the statistics on drugs and alcohol, for starters. Teenage girls today are four times more likely to drink than their mothers were. They're fifteen times more likely to use drugs than their mothers were. Traditionally, alcohol abuse has been more of a problem for teenage boys than for teenage girls. Not anymore. In a report published in 2004, the National Research Council reported that young teenage girls are now more likely than boys to be drinking alcohol regularly—not because boys are drinking less, but because girls are drinking more.

If girls have closed the gender gap with regard to alcohol abuse, boys are still more likely to be getting into trouble with drugs. According to FBI statistics, the number of boys under eighteen arrested for drug abuse offenses has increased by more than 50 percent in the past ten years; boys under eighteen are still five times more likely to be arrested for drug abuse violations than are girls under eighteen. In chapter 7, I'll explore how the cultural and professional neglect of sex differences has compounded the drug problem.

But school, not drugs, is the "new" problem for boys. While today's girl is more likely to have problems with drugs and alcohol than her mother was, today's boy is much more likely to be struggling in school than his father was. Boys today are increasingly alienated from school. Recent investigations have shown a dramatic drop over the past twenty years in boys' academic performance in American schools. According to the United States Department of Education, the average eleventh-grade American boy now writes at the same level as the average eighth-grade girl. Similar gender gaps have been documented in the United Kingdom, Australia, New Zealand, and Canada. And the percentage of boys going on to college, and graduating from college, is falling. The U.S. Department of Education now projects that in the year 2011, there will be 140 women graduating from college for every 100 men—very nearly a 60/40 female-to-male ratio.

The future may already have arrived. Several major U.S. colleges and universities, such as New York University and the University of North Carolina, already report that their student body is more than 60 percent female. I'm all in favor of women's colleges, but you have to ask the question: Why are nominally coed schools looking more and more like all-women's colleges? The proportion of boys going on to college is dropping steadily, as is the proportion of young men who are sticking around long enough to graduate. The high school dropout rate in the United States is now close to 30 percent, and the great majority of dropouts are boys. More and more boys, discouraged by years of failure in elementary school, middle school, and high school, are asking: "Why should I stick around for any more of this?" Later in the book we'll hear from teachers who know how to use gender differences to kindle real enthusiasm for learning in both girls and boys.

Still, many educators and policymakers stubbornly cling to the dogma of "social constructionism," the belief that differences between girls and boys derive exclusively from social expectations with no input from biology. Stuck in a mentality that refuses to recognize innate, biologically programmed differences between girls and boys, many administrators and teachers don't fully appreciate that girls and boys enter the classroom with different needs, different abilities, and different goals.

Excerpted from Why Gender Matters by Leonard Sax, M.D., Ph.D. Copyright © 2005 by Leonard Sax, M.D., Ph.D.. Excerpted by permission of Broadway, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.