Alex Negelein admits that when there’s something he really, really wants, he’s willing to ask his dad for it “150 times.”

The 9-year-old’s pestering may be on the extreme side, but he’s hardly alone. A new survey has found that, even when their parents say “no,” nearly six of 10 young people keep nagging an average of nine times.

The survey, released Monday, also found that 10 percent of 12- and 13-year-olds said they asked their parents more than 50 times for products they had seen advertised.

Officials at the Center for a New American Dream, who commissioned the survey, call it the “nag factor.” They say it shows that kids while annoying their parents are feeling pressure from peers to buy the latest products.

“They are being made to feel that if they don’t have the right low-cut designer jeans, the right video game or the right designer watch, they aren’t going to have a friend that they’re going to be rejected by other kids, ” says Betsy Taylor, executive director of the Takoma Park, Md.-based center, which promotes responsible consumption of resources and goods.

Of those polled, about a third said they felt pressure to buy certain products, and more than half said that buying those products made them feel better about themselves.

When it comes to nagging, 55 percent said they could usually get their parents to give in.

The poll, which has a margin of error of 3.5 percentage points, included the answers of 750 American youth, ages 12 to 17, who were contacted by phone last month. But experts say nagging is a habit learned much earlier.

Marian Salzman, chief strategic officer for the ad agency Euro RSCG, says about 60 percent of the young people the agency has interviewed for research said they knew how to manipulate their parents on “small things” before they started first grade.

And, increasingly, even the youngest children have spending power an estimated $52 billion for ages 4 to 12 by 2006, compared with a projected $40 billion this year and $17.1 billion in 1994.

All of that has made nagging an “art form”, says Salzman, who believes parents have only encouraged it by giving children much more say in family decisions.

Alex’s dad, Chris Negelein, has instituted a rule: “Ask once, and only once.” He says, with the help of counseling, Alex is learning to follow it.

And if he doesn’t, he knows what happens.

“We have to leave the toy section,” Alex says with a sigh.

“You try to set the ground rules to teach your kids that materialism is a means to an end, but it’s not a means to life,” says Negelein, who is divorced and took custody of Alex a year ago to try to rein in his behavior.

But he admits it’s sometimes difficult not to weaken, especially with the waves of licensed products that accompany every blockbuster movie.

In the long run, Taylor says she hopes the Center for a New American Dream can help persuade Congress to pass laws further limiting advertising to young people. But ultimately, she says, it’s a parent’s responsibility to set better limits and stick to them.

Melissa Cooney, a 15-year-old from Indianapolis, believes that’s true.

“If we are spoiled,” she says, “it’s kind of the parents fault, too, for giving in to us.”