Boys and girls are different. A shocking exposé, I know, but in a topsy-turvy world where marriage between a man and a woman has to be vigorously defended, it now commands a certain profundity.

An educator named Michael Gurian, who has taught at Eastern Washington University, along with Gonzaga University and Ankara University, has made a career out of proclaiming the differences between boys and girls. He has written extensively, citing solid scientific data, on how boys and girls have different brain anatomies and so process information specific to their sex. He is also quick to temper these findings with the caveat that there will always exist variations and exceptions to rules. But any parent who has male and female children already knows much of what Gurian’s scientific evidence reconfirms.

The reason I know about this educator is because we have sent our sons to an all-boys Catholic high school — one that has embraced the teaching strategies promulgated by Gurian.

That the school would embrace the Catholic faith with the same vigor is a thing devoutly to be wished. But I digress.

The teachers at this school are instructed in specific techniques, the goal being to manage an all-male classroom in such a way that the teachers bring out the best in their students.

My wife and I have seen the results in our own sons and have become true believers in this method. I don’t get a kickback for saying this, but if you want to know more about just how clearly different a boy’s brain operates from a girl’s brain, read Gurian’s books. His latest is called The Purpose of Boys: Helping Our Sons Find Meaning, Significance, and Direction in Their Lives (Jossey-Bass, 2009). I highly recommend it.

A few weeks ago, Gurian visited our high school to give a lecture to the parents. The gym was packed and the evening enlightening. The lecture wasn’t just part of a book-promotion tour; it was packed with sobering statistics documenting that boys are falling behind in our culture — and fast. Why? Because so many social engineers and holders of power in the elite institutions of America cling to the notion of the gender-neutral “nurture over nature” fallacy.

We learned that, although teenage girls attempt suicide more often than boys, boys are much more likely to succeed. Their attempts are more than cries for help. Boys (and then men) are incarcerated at much higher rates than girls and women, and boys are much more likely to be diagnosed with an attention disorder than girls. It all adds up to the bracing statistics showing that more girls than boys go to, and graduate from, college.

As the father of a daughter, I’m all for educational opportunities for girls and young women. Still, the thought of a large segment of the future population being young, male and undereducated is unsettling.

But this isn’t about the education of boys and girls. If you want to know more about that, read Gurian’s books. (As this is the second plug I’ve given him, he should at least send me an autographed copy of his complete oeuvre.) No, this is about an epiphany I had while I was listening to Gurian’s lecture.

Gurian spoke about the chemical mechanics of female and male attraction as his talk veered into another important subject for parents of teenage boys and girls. The professor wasn’t here in the guise of a moral theologian or sexual ethicist. He was strictly giving us a primer on how chemicals in the bodies of girls and boys react so differently to create a bond.

That’s when I had the epiphany: God really did know what he was doing when he instituted the sacrament of marriage.

I know that more than ever after hearing the scientific explanation of that pesky little hormone oxytocin. Women are loaded with it; men, not so much. When a woman hears a baby cry, her levels of oxytocin increase. It is, according to the expert Gurian, a bonding hormone. We’d seen it in action even before the lecture began. When the 6-month-old baby of a teacher began to squawk, my wife made a beeline for the little guy. She instantly started fussing over little Dominic.

I didn’t think much about it then. My wife is always doting on a baby. But then I learned all about oxytocin. Men get shortchanged in the oxytocin department. We tend to produce a lot of testosterone, and when that goes unchecked, anything can happen. But that’s another story, too.

According to Dr. G, there is a time when the levels of oxytocin in women and in men reach equilibrium. To put it delicately, it is the moment after intimate congress. At that moment in time, women and men are flush with this incredible bonding chemical. Here comes the tricky part. In women, these elevated levels can last for months. In men, they can disappear in an hour. Testosterone takes over. Again.

Now, God made testosterone and so it is good. It comes in handy when you’re trying to land your first woolly mammoth or nail your PowerPoint presentation for the head honchos. But it can get in the way of a healthy man-woman dynamic.

Enter marriage — sacramental, holy, committed matrimony. It’s the only sacrament where the people receiving the sacrament are actually their own ministers. Just the bride and groom in front of an altar making a promise to each other before God: simple and to the point.

Covenant. It’s what God uses to keep something worthwhile together through good and bad times. It comes in handy especially when people you have seen through deprivation, slavery and humiliation begin worshipping golden bovines only a short time after you arranged a covenant-bound deliverance. And it must have been equally important to have a covenant in place when the only begotten Son God sent down to earth was left battered, beaten and hanging on a cross between two criminals.

And since God designed us with these peculiar and necessary chemicals that create attraction and bonding, he likewise instituted something sacred and profound to tide us through when the chemicals run low or the times get tough.

I live in a state that has recently passed a proposition declaring marriage to be the bond between one man and one woman. That same state is in the process of developing another proposition in the not-too-distant future to overturn that vote. These follies notwithstanding, the more science we understand, the more beautiful God’s plan for his creatures — especially male and female in the bond of holy matrimony — seems to be.

Thanks, Dr. Gurian, for telling us what most of us already knew.

Robert Brennan writes from Los Angeles.