In his new book, New York Times columnist and author David Brooks promises to deliver "the happiest story you've ever read. It's about two people who led wonderfully fulfilling lives." He goes on to say that this fictional couple -- Erica and Harold -- who arrive at success from opposite paths, relied more on their subconscious instincts than on the more measurable rational side of their minds.

Still with me? Oh, good. If this smells like a doctoral thesis disguised as a harmless, general interest book, you have a keen sense of smell. "The Social Animal" is a Brooks' Big Idea book. It probably will not be the happiest tale you've ever read, but it is a hopeful account of life's twists and turns as viewed through Brooks' familiar conservative lens.

Give Brooks credit. He takes on some ambitious questions: How do we become the people we are? What guides our most important decisions, such as career, love and political leanings? Does life's journey consist of continual, built-upon layers or is it more like a series of fragmented moments? Can IQ predict success?

Thank goodness the answer to that last question is no. Brooks "discovers" that "at best IQ contributes about 20 percent to life success." Hurrah!

Harold is the product of the very attentive white middle class. His dutiful parents hovered like helicopters and cleared the path like bulldozers, all in the cause of providing the very best for their son. College and personal growth were the expectations, and Harold did not disappoint.

"Harold was part of a hereditary meritocratic class that reinforces itself through genes and strenuous cultivation generation after generation."

At first glance, Erica had more obstacles to overcome. Theoretically, she should not have succeeded, but she did. Her socioeconomic status balanced perilously between middle class and poor. She made her own breaks. Her mother was Chinese and her mostly absent father was Mexican-American. This combination would turn out to be one of her stronger assets when she stepped into the business world.

"In a business world filled with engineers and finance people, she would know culture. That would be her unique selling proposition. There would always be a market for skills like that. After all, how many female Chinese-Chicana workaholics from the ghetto does anybody know?"

Erica and Harold eventually meet (at a Starbucks) and marry. Perhaps this is the happy part Brooks promises. Their story gives the book its narrative thread, but that thread is often lost because of Brooks' irritating tendency to support every fact with at least five research studies when most of us with average IQs probably can only remember a couple. The social science data make for great cocktail party chatter. I learned that marital satisfaction declines 70 percent after a child is born, and that a woman loses 700 hours of sleep in that new child's first year.

Consequently, "The Social Animal" feels stuffed, like one of those pizzas in which the crust is filled with a half-dozen indistinguishable cheeses. Or like a thesis.

Stephen J. Lyons' new book is "The 1,000-Year Flood: Destruction, Loss, Rescue, and Redemption Along the Mississippi River."