NEW YORK — The hot spot du jour of Manhattan nightlife looms large over Fifth Avenue and 42nd Street, where crowds of stylish YoCos — young cosmopolitans — were jostling inside one evening last week for the right to pay the $15 cover. Rather than crossing the velvet ropes for a rave, house party or disco, the hip patrons were packing into a controversial lecture at the New York Public Library on the modern meaning of feminism.

In New York and other urban centers, gray matter is the new black of the hip social scene. Thousands of young singles and couples are eschewing the perfunctory dinner and a movie for a growing circuit of late-night museum prowls, Oxford-style debates with pre-feud cocktail parties and book readings with cash bars and after-hour bands.

It is, observers of the trend say, a visceral backlash to life in a Paris Hilton world. It’s a chance to impress a mate, or a potential date, by flexing a body part that has lost ground in recent years to biceps and pecs — the brain.

“Let’s face it, there really is nothing more sensual than caressing someone’s mind,” said Paul Holdengrdber, who launched the library’s live lecture series that is now a staple of New York’s “intellidating” scene. Two years ago, the average age at library lectures was 68. It is now 41 and falling, driven down partly by a new crop of cutting-edge guests including underground cartoonists Robert Crumb and Aline Kominsky-Crumb and director Jonathan Demme.

“Intellidating,” coined in England in 2002, sprang from “Intelligence Squared,” a live discussion series launched by a couple of British moguls whose professed aim was to make debating “sexy.” Heated debates on topics ranging from “Monogamy Is Bad for the Soul” to “Maggie Thatcher Saved Britain” brought in the London glitterati, including actor Hugh Grant and, until their split in February, girlfriend and socialite Jemima Khan.

The concept leapt across the pond to New York last year with the American version of Intelligence Squared — IQ2US — launched by philanthropist and businessman Robert Rosenkranz. Housed inside the Asia Society building on the Upper East Side, the popular events have lured a following including conservative pundit Monica Crowley and her boyfriend, the venture capitalist Bill Siegel. The cheaper seats are peppered with budding young brainiacs who find heightened stimulation in verbal joust.

A 45-minute cocktail reception precedes each debate, after which comes a cranial lucha libre where, on one night, author Michael Crichton sparred with other panelists on global warming.

“The debate itself was far more heated than I’d expected, and Kate and I disagreed completely,” said Andy Criss, 28, who took Kate Lauber, a 25-year-old Columbia University American studies major, to an IQ2US debate titled “Is America Too Damn Religious?” for their second date.

A Web site called “The Right Stuff,” which advertises that “smart is sexy,” bills itself as a place where lonely-heart Ivy League graduates can find their match. IntellectConnect, a Washington-area company, launched in August 2005 and has 6,000 members, according to co-founder Cindy Embleton.

At Housing Works Used Book Cafi in Soho, Friday night book readings have become lounge-like events with live bands and cash bars. Last year, New York’s Museum of Modern Art began PopRally, an event aimed at young couples and singles that mixes cocktails, music and art.

Last month, the Hirshhorn began a series of museum nights with a sold-out event in which 1,700 Washingtonians mingled amid a new installation exploring how artists use light. Revelers heard music spun by a DJ and selected to capture the essence of the art. Later, some revelers broke off from the cash bar on an “insomniacs tour” of the galleries.

“I just went there to do something fun, but of course, this is Manhattan, and the Jewish community, so everything is really a singles event even if it’s not,” said Dorron Lemesh, a software writer who attended his first Makor spelling bee three weeks ago.

All comments will be screened and may take several hours to be posted. • Comments that are off topic or include inappropriate content (offensive language, libelous statements, personal attacks) will not be approved.

• Please do not include contact information or last names, as we cannot verify your identity and some writers may seek to misrepresent their identities using this forum.

• We will rarely edit or alter your comments. They will either be approved or declined, so please double-check your submissions to make sure they meet our guidelines.

This is cache, read story here