CARNAL NATION

How Sex Works:
Why We Look, Smell, Taste, Feel,
and Act the Way We Do
By Sharon Moalem
Harper Collins
26.99, 288 pp.

Back during the beginning of railroads, many stations had a book lending program. You'd rent a book from your starting station and then return it to the store at your destination. It seems like an eminently sensible system, and How Sex Works by Dr. Sharon Moalem is the perfect book for it. It's almost ridiculous to issue a book like this in hardcover 'cause we all know where a book like this—a slight 230 pages promising to answer provocative questions abut sex and attraction—lives and breeds: the airport bookstore's 2-for-1 paperback section. New York Times columnists make up about half of this section's ecosphere and Dr. Moalem, with many TV-friendly appearances and another Times bestseller under his belt, is no exception. The song title chapters practically beg you to treat it lightly.

Mary Roach's Bonk casts a shadow on How Sex Works. It's hard not to see it as a cynical plot to ride Ms. Roach's runaway coattails in the short commute friendly-Nonfiction sex racket. Of course, one man's cynical ploy is another man's marketing genius, but while Bonk dug out stories of the strange-but-true meetings of sex and research, Why Sex Matters settles for Biology 101 lessons and cocktail-party tidbits about the science of attraction. It's familiar enough stuff to anyone who ever sat though an entire Discovery Channel marathon during a sick day. It's an accurate enough look at current knowledge and belief, but old news to people keeping up with the science of sex.  Sharing the trvia and fun facts would be beyond the point, because all the book is is a series of facts, studies, and "You may think...." ledes. There is none of Roach's odd adventures or sarcastic footnotes; How Sex Works's notes are in the college lecture mood.

Still, the breezy tone keeps things quick, with the wry, distracted mood that I think comes as part of the NYT employee benefits package. Sometimes a little too distracted. Dr. Moalem seems much more comfortable talking about chemical reactions, internal swelling, and pubic lice than talking about actual sex between actual people.

But that's just nit-picking. It's hard to fault a book about actual science presented in such a slight, easily-digestible away. It's progressive enough to give to your Aunt Ida and short enough to cover a connection from O'Hare to Newark. You may just want to leave it on the seat for the next person.