There is no question that a baby's cry can cause a high level of discomfort and stress for the listener. Consider the fact that the United States military reportedly used the sound of screaming infants – played over speakers - to train the Navy’s elite SEALs to endure psychological torture! Every year, roughly 15 per cent of newborns are born with colic – a condition that is diagnosed when a baby cries for more than three hours per day. All things considered, it’s hard to believe that more parents of colicky newborns aren't institutionalized each year. Parents and doctors have remained flummoxed by the question of colic – its causes and cures – for ages. Dr Harvey Karp is one of North America's leading paediatricians on the subject. His best-selling DVD and book, The Happiest Baby on the Block, has helped millions of parents cope with colic in newborns. We reached Dr. Harvey Karp for this Q&A at his office in Los Angeles. Q. What do we know today about colic and its causes? A. For thousands of years, we thought that colic was an intestinal discomfort that babies had, either caused from overeating or having stomach gas. They would double-up and seem to squirm in pain and often pass gas. In fact, the word colic comes from the same basic word as the word colon. Children would be treated with all sorts of things, from extra burping to hot water bottles for the stomach to special formulas. Studies have shown that, in western cultures, most babies cry and fuss for about an hour or an hour-and-a-half per day, but some at least 15% will cry and fuss for more than three hours, which is the medical definition of colic. You'll notice it doesn't say anything about the cause of the crying. Q. What’s your opinion about the cause of colic? A. I believe the key to understanding colic is that our babies are born three months before they're really ready for the world. And because of that, they have this funny combination of being over-stimulated, on the one hand, and terribly under-stimulated, on the other (the latter being the much bigger problem). In the womb, the baby has a non-stop symphony of sensations. He or she is being held, touched, and jiggled, and hears the non-stop sound of the blood flow, which is louder than a vacuum cleaner, 24/7. So to bring a baby into your house and put them in a dark, quiet room by themselves is actually sensory depriving. Some kids can tolerate that, and some kids just fall apart without the stimulation that they had inside the womb. And, what I observe in my work is that when you imitate the sensations of the womb, it doesn't just reassure them – it literally flips a switch. It turns on a calming reflex that all babies have at birth. Q. What are some things that parents can do to simulate the womb environment, then? A. There are five unique steps that parents can do to imitate the womb and turn on the calming reflex, I call them the “Five S’s”. The first “S” is swaddling with the arms down. The second “S” is the side or stomach position. (Lying on the back is the only safe position for a baby to sleep in, but it's the worst position for calming a crying baby. So when they're crying, pick them up in your arms and roll them to the side or stomach position.) The third “S” is shushing, which imitates the sound in the womb – when a baby is crying, you have to shush literally as loud as he or she is crying, which can be as loud as a hair dryer. (Once you’ve calmed them down with that loud shushing, you can decrease the intensity a little bit.) The fourth “S” is a swinging or tiny jiggling motion, no more than an inch back and forth. (You can achieve this by sitting on the edge of your bed bouncing, sitting on an exercise ball, dancing around the house, going for a walk on a pebbly walkway to get that bouncing in the stroller, or putting your baby in a sling for a nice long walk.) The last “S” is sucking, once you've calmed the baby down. Some fussy babies will suck right away. Sometimes they'll be hungry, so nursing them will calm them down. But usually, once you've calmed them with the other “S’s,” the sucking is like the icing on the cake that gets them to an even more profound level of calm. Q. Can you describe what happens to first-time parents who have a colicky baby? A. Everyone pictures having the perfect baby who is going to be cuddly and sweet and never have any problems. So it's very unnerving to have a baby who cries and cries for long periods, and nothing makes you feel worse than not meeting your baby’s needs. It's even more serious than that, because it turns out that crying and exhaustion are the number one triggers for some serious problems like marital stress, postpartum depression, shaken-baby syndrome, breastfeeding failure, and even sudden infant death syndrome and suffocation, because babies cry so much that the parent will bring the baby into bed with them and accidentally get the baby in an unsafe position. It also leads to parents starting smoking again, and to obesity (because exhaustion unbalances your metabolism – making you crave sweets and fats - and it also undermines your will power). Besides making you feel incompetent, then, having a colicky baby actually leads to a whole host of serious and expensive medical issues. Now, colic usually peaks at about six to eight weeks of age, and usually by three to four months of age it's pretty much passed on its own. But if you can do those Five S's during those first few months, you really can help your baby settle faster. Interestingly, the more you do the Five S's, the faster your baby will responds to them. Babies learn that those things are going to calm them down. Q. In your DVD and book, you described ancient lessons that we can learn from African bushmen on how to avoid colicky babies – most notably, holding babies as much as possible and breastfeeding them regularly throughout the day. How can modern American parents implement this kind of care? A. There are many things that we can do to imitate what people do in Africa, and even to be better and more effective than the moms in Africa. Holding your baby, ensuring skin to skin contact, carrying your baby in a safe sling, and nursing – those are all wonderful ways of meeting your baby's need for contact and for nurturing stimulation. In addition to that, we've got things like white-noise MP3s and CDs, swaddling blankets, and reclining swings that can make the baby feel like he or she is in your arms when you have to leave to take a shower or cook dinner. And of course there are pacifiers if you're not going to be available. So there are a lot of tools that we have to allow us to be effective caregivers.