04/03/2007 AT 02:30 PM EDT
One sure way to win Ivanka Trump's heart? A high IQ.
"My friends always joke that I'm going to marry a 90-year-old Pulitzer Prize winner," Trump, 25, told PEOPLE backstage at Dressed to Kilt
, an annual fashion show benefiting the Friends of Scotland charity in New York. "I love smart, intelligent men. That's the No. 1 one thing that keeps me interested, in the long term."
Still, she says, "I mean, it's great to go on a few dates with somebody who's gorgeous and maybe doesn't have anything else to say, but [intelligence] is the most important thing to me in the long-run – and a sense of humor doesn't hurt."
Though she's been linked at various times to both Topher Grace
(last November) and Lance Armstrong
(last October) – Ivanka's father, Donald Trump, advised her
to date a jock. "He loves the athletes because he's always wanted to be an athlete."
But at the moment, "I'm not dating anyone exclusively," she says.
As for Grace, they remain "very good friends," she says, but they are not dating – which is fine, because, she adds, "It's amazing being single. I actually think I like nothing more."
Not that this is necessarily a permanent condition, either. "When the right guy comes along, he comes along," she says. "But until then, I'm happy."