Parents who spank their child know they are hurting the little one's back side, if even a little bit. But emerging studies show they may be damaging the thinking end as well.

New research from the University of New Hampshire claims spanked children have lower IQs than those whose caregivers spare the rod.

University of New Hampshire Professor Murray Straus and colleagues studied nationally representative samples of more than 17,000 2- to 9-year-olds in 32 countries. When they re-tested four years later, researchers found the younger and more often kids get spanked, the more impact on their brains.

The connection between spanking and smarts doesn't seem like brain surgery to Dr. David Finn, a psychologist specializing in parenting and domestic violence who teaches positive discipline techniques at Associates in Human Development Counseling in Rolling Meadows.

"It'shard for a child to develop trust when the same person who can heal a skinned knee with a kiss can also inflict pain at will," Finn says.

Corporal punishment goes hand-in-hand with blocked brainpower because it becomes a chronic stressor for young children, research shows. The anxiety shows up like symptoms of post-traumatic stress as toddlers grow constantly fearful and easily startled. That means crucial connections in the brain donít hook up and IQ digits dip, experts found.

Street smarts

In the mid-'90s, Straus, a national anti-spanking guru, published a precursor to this yearís study, "Beating the Devil out of Them: Corporal Punishment in American Families and its Effects on Children." It established that corporal punishment produces the opposite of the desired effect. His new study shows that in prosperous countries, fewer parents use corporal punishment and national IQ averages are higher.

In a metro area that is becoming a national poster city for youth violence, Chicago public policy experts are looking to parenting techniques that offer alternatives to corporal punishment as a possible root fix for wildly escalating hostility among inner city young people.

In spite of mounting evidence that spanking a tot (or a teen) does more harm than good, spreading the anti-spanking doctrine is still a hard sell, Finn and other Chicago area parenting professionals say.

"Parents learn to parent from their own parents, so they seem to think it is their right to spank," Finn says.

Rush University College of Nursing professor Dr. Deborah Gross got that message right from the mommiesí mouths when she rounded up a test group of low-income parents to shape The Chicago Parent Program. This training program now helps families in Chicago's inner city youth programs and Head Start centers.

When leaders of the focus group asked how many parents in the room had been spanked as a child, everyone raised a hand. In fact, the parent advisory group said giving time-outs instead of spanking was a prime example of why they view white kids as "spoiled and ìill-mannered," Gross says in a paper about the program.

Hard sell

Gross quickly got the message that billing the workshops as a no-spanking program would assure it also would wind up as a no-participant program.

"You lose that war," she says. "It's hard for parents to understand the toxic effects of spanking because a lot of them were spanked and still felt loved."

Instead, The Chicago Parent Program of Rush University created eight keys to effective discipline that gently nudged parents away from hitting and toward subtler, gentler forms of getting behavior changes.

"A lot of these parents told us they don't want to spank their kids. They just don't know what else to do," Gross says. "We gave them other tools they could use to get the behavior they were looking for."

Much to some parents' surprise, nonviolence worked. Parents in training interventions reported they resorted less to yelling, spanking and hitting than comparison groups, Gross says. And the kids were behaving better. Follow-up surveys and observations showed children of parents who completed training werenít whining, back talking or acting out so much at day care.

Research from at least one national study found that kids whose families go through first-rate parenting programs like The Chicago Parent Program wind up with 60 percent fewer arrests.

Whatever works

Most of Finn's clients don't come from inner city neighborhoods, yet as many as 80 percent of them grapple with good ways to discipline their offspring, he says. But, in the suburbs as well as the city, turning away from the quick fix of a whack to the backside can be tough tactic to reform.

"Parents get short-term reinforcement from spanking because the child stops the offending behavior, looks downcast and apologizes," Finn says. "What they donít realize is that the child is really learning how to get away with it, to fear the parent and to be less honest."

It's not just that spanking is harmful to the growing minds of toddlers all the way up to teens (the strongest link between corporal punishment and IQ found in the study was for those spanked as teens). Finn and Straus both say that, for all its instant feel-bad upshots, spanking simply doesn't work.

"I tell parents that if spanking worked, theyíd only have to do it once," Finn says. "Instead, they end up having to do it over and over and resorting to escalating levels of violence."