MAIN LINE WASP <i> by W. Thacher Longstreth with Dan Rottenberg (W.W. Norton: $19.95; 310 pp.)</i>

Some biographies are instructive not so much because of the particular achievements of the subject but because the subject represents a type or class. Thacher Longstreth acknowledges his representative importance by calling his autobiography not “My Life” but “Main Line WASP.”

The autobiography of the Princeton All-American football player turned top Life magazine salesman and contender for the mayorship of Philadelphia defines the stereotype of WASP, and while his title clearly states the fact, not all of it can possibly be conscious. A photograph of the young Longstreth with his bride in 1941, strategically paired with a shot taken on their return to the very same spot in 1966, attest to the graceful aging of the strong WASP bone structure--aided, it is subtly implied in the book, by honest living.

WASPs may play the wimp (the terrible epithet George Bush had to live down in his presidential campaign), but they know how to play it to uncanny advantage. Longstreth tells the story of a rival who applied all sorts of unflattering epithets to him, the least of which was ineffectual . Longstreth, when contacted by the Philadelphia Inquirer to respond, admitted that he had failed his colleague in a certain matter, and that the man had every right to be disappointed. Asked by the Inquirer whether the language in which the colleague expressed his disappointment was not a little strong, Longstreth replied, for publication: “No. Ed and I have been friends for a long time, and we’ll be friends for a long time to come. There’s nothing to be upset about.”

The bad-mouther was on the phone to Longstreth as soon as the article appeared. “Goddammit, you have me so embarrassed,” he complained. “My wife is so angry at me. All of a sudden you’re the good guy and I’m the villain. You’ve taught me a lesson, Thacher. I’m never going to say a mean word publicly about anyone again.”

Take this species of killer-innocence (notice the charitable inclusion of the rival’s promise never to sin again), coupled with the absolute confidence that comes from belonging to a strong network of like individuals, and the nice-guy approach can be wielded like a club. Longstreth’s colorful stories of business and politics, including the tale of his unintended selection as middleman between Philadelphia Teamsters and Jimmy Hoffa, make enlightening reading, and belie his contention that the WASP’s day was over in the 1930s.