Is mankind really in a slump? And if so, why?

Stanford University Medical School Professor Gerald Crabtree theorizes that the apparent decline in our collective ability to cope with life’s challenges stems from an accompanying drop in human intelligence.

In a two-part study titled “Our Fragile Intellect,” the geneticist writes: “I would wager that if an average citizen from Athens of 1000 B.C. were to appear suddenly among us, he or she would be among the brightest and most intellectually alive of our colleagues and companions, with a good memory, a broad range of ideas, and a clear-sighted view of important issues. Furthermore, I would guess that he or she would be among the most emotionally stable of our friends and colleagues.”

Hey, we 21st century folks would be more emotionally stable, too, if we didn’t have to put up with email spam, traffic jams and campaign commercials.

Fortunately, plenty of experts dispute Dr. Crabtree’s thesis. They point to rising scores on IQ tests over the last century.

Then again, some people who do well on such tests seem mighty dim on many practical levels.

And Dr. Crabtree does make a troubling point when he writes: “Needless to say a hunter gatherer that did not correctly conceive a solution to providing food or shelter probably died along with their progeny, while a modern Wall Street executive that made a similar conceptual mistake would receive a substantial bonus.”

At least Prof. Crabtree offers this upbeat perspective on the downward trend he detects:

“Although our genomes are fragile, our society is robust almost entirely by virtue of education, which allow strengths to be rapidly distributed to all members.”

But how much “education” should be required to break the stunningly stupid — and widespread — habit of texting while driving?