The "Happiest Baby" guru – Dr. Harvey Karp – was in the Twin Cities Thursday to ask Target corporate leaders to sell and promote a combo product that features a CD to help babies sleep along with Halo infant sleepwear.

The underpinning of Karp's Happiest Baby philosophy and best-selling book is that babies are born before they are ready and that parents can help them sleep by simulating the womb environment for them. This includes swaddling them in tightly-wound sleepwear (a la his alignment with Halo), swinging them in just the right way and making shushing noises that simulate the sound babies hear inside the womb.

"Babies are born with an off switch for crying called the calming reflex -- a virtual off switch for crying and an on switch for sleeping," Karp said in an interview.

Karp's CD consists of "white noise" that simulates the sound. (When my son was born, we created white noise in his room with an air purifier, though not necessarily for this purpose. Karp said that noise is higher-pitched than the sound inside the womb.)

One study out of Penn State University found Karp's methods increased nightly sleep for babies by 45 minutes, and reduced babies' weights (presumably because parents didn't shove bottles in their mouths as much to get them to sleep). Another study from a children's hospital in Virginia found the methods could calm most colicky babies in 30 seconds.

Karp said this approach has other potential benefits, including making it easier for parents to put their babies to sleep on their backs. That reduces the risk of SIDS (sudden infant death syndrome). There might be fewer smothering deaths that occur when exhausted parents keep babies in bed with them to help them get to sleep and then roll on them, he said.

"When babies sleep better -- even if you get an extra hour of sleep -- that's golden. If you can get your babies to sleep 4 hours at a stretch instead of 2 hours at a stretch, that's major," he said. "When you're exhausted, you're the equivalent of drunk in terms of your reaction and awareness."

Karp certainly isn't the only expert on parenting newborns, but his methods have attracted quite a few believers. The Minnesota Department of Health in 2009 encouraged local health departments to use his methods in their home visit programs for new mothers. (However, the department noted that his methods didn't meet their definition of "evidence-based," meaning there wasn't yet enough research to back all of the claims.) What do you think? Have you tried any of his methods? Did they work?

Karp has now moved on to toddlers with a new book – The Happiest Toddler on the Block. His theory is that toddlers are like cavemen whose primitive responses and tantrums should be expected until parents give them the proper guidance. He cited a study showing that his methods can cut 50 percent of toddler tantrums.

"We call it 'going ape.' You get so mad, you just go ape," he said. "(Toddlers) start out ape. They're not good with language or logic or reason -- even on a good day."

The tone of parents' responses is key, he said. Matching their emotion isn't productive, but staying too calm doesn't work either. It might calm parents down, he said, but it can agitate the children more.

"When they're upset, we need to communicate to them in a right-brained type of language," he said, "a language that uses short phrases, lots of repetition and with about a third of their emotion."

There are tons of Karp excerpts on YouTube. Here is one of them: