(FORTUNE Magazine) – If two heads really were better than one, nobody would need to read this pair of books, which, from different vantage points, take aim at the same problem: group stupidity. Persons individually smart, when put into groups, have arrived at decisions fabulously dumb: Quaker Oats' decision to acquire Snapple; Xerox's decision not to exploit the fax machine, which it was first to get to market. How about those swell O-rings on the Challenger? Or our space telescope--the befuddled Hubble?

You might think smart people--corralled and given proper surroundings (Barcaloungers, zither music, free copies of the Utne Reader)--would just naturally produce clean, clever, correct answers to questions put before them. Often as not, however, you'd think wrong.

And wrong thinking is exactly what authors Spitzer and Evans seek to eradicate with Heads You Win. They begin by asking an arresting question: How did past greats of American business--the Watsons, the Fords, the McCormicks, the Penneys, men without graduate degrees, men who were ignorant alike of feng shui and reengineering, men who lacked not just Covey but the modern world's whole covey of Coveys--manage to stay in business? It's because, the authors say, these gaffers were great at a basic skill too little esteemed today: problem solving.

The authors' stress throughout is on the practical, the sort of common sense that, being rarely heard, compels readers to smack themselves on the forehead and exclaim, "How true!"

Case in point: engineers at Chrysler's Jeep Cherokee operation who awoke one morning to find that seams on sun visors were starting to burst open. President Robert Lutz asked what the engineers intended to do. "Redesign it, with a different seam," was the answer. That would take how long? Several months. Lutz then asked if anyone had stopped to consider why this defect had never before appeared in the car's many years of manufacture. Well, no; nobody had. It turned out the problem lay with a subcontractor whose sealing machine had worn out. Easy and immediate fix: replace it.

Lesson? "The initial objective of problem solving," say the authors, "is not to solve the problem, but to keep from doing something stupid." Step one should always be to eliminate red herrings. Says Isaiah Owens, a manager of logistics at Pepsi quoted by the authors: "I tell my people to quickly rule out what didn't cause the problem, so we don't start fixing things that aren't broken."

What Spitzer and Evans eventually lay out for readers is an intellectual road map--a set of directions any group can follow to get from problem to solution.

Warren Bennis's Organizing Genius gives readers something different but complementary. He and co-author Biederman describe hallmarks that distinguish extraordinary groups from groups whose performance is strictly so-so. The former, which he dubs "Great Groups," include Walt Disney's animators; Lockheed Martin's Skunk Works, whose engineers produced the Stealth fighter; and the Manhattan Project, makers of hot, iridescent oblivion. What traits did these and other Great Groups share?

The thrill of knowing is diminished, somewhat, by Bennis's admission that the traits are predictive only in their absence: Having them won't guarantee greatness; not having them, however, is a one-way ticket to Fresno.

A surprising trait all share: crummy quarters. The Skunk Works did some of its best problem solving under a rented circus tent. The members of Great Groups are never realists. They're optimists, convinced they can do anything. The appeal of animation, for example, seemed iffy at first to Hollywood sages. Among the doubting realists whom Disney ultimately silenced was MGM's L.B. Mayer, who asked during the making of Snow White, "Who'd pay to see a drawing of a fairy princess when they can watch Joan Crawford's boobs for the same price?" Lots of people, it turned out. (No disrespect to Ms. Crawford.)