5. Yield left. Whether Mom and Dad are righties or southpaws, studies indicate that they have a universal preference to cradle infants on their left side -- over the heart. In fact, a recent study from the University of Provence, France, found that a whopping 66 percent of caregivers followed this trend. Research suggests the parents' heartbeat helps soothe a baby on the left side, while the right side arouses, excites, and gets the baby's attention. Whether on your left or right, the little bundle cradled in your arms will soon be able to read rapture written all over your face. Just you wait and see.