If you happen to be the type of person who carries kids on your left hip instead of your right, you may be surprised to find that you're in the majority. In fact, Science Daily writes that over two-thirds of people prefer to carry children on their left hip instead of their right, and the reason is actually somewhat scientific.
A study, published in a recent edition of the Neuroscience and Biobehavioral Reviews found that between 66 and 72 percent of people hold an infant on their left side. That number jumps to 74% for those who are right-handed and drops to 61% for those who are left-handed. Lead author of the study Julian Packheiser says they looked at more than 40 different studies on this subject before coming up with their own conclusions. "In order to explain the effect, we looked for all of the studies we could find on this topic," Packheiser stated. The is also pretty similar among both men and women, with 64% of men and 73% of women favoring their left side.
The study found that "since emotions are primarily processed in the right hemisphere of the brain, people may also tend to move their baby into their left visual field, which is linked to the right hemisphere of the brain." Basically, since the right side of your brain controls your emotions, people tend to hold their babies on the left side so they can more easily access those emotions.
A study in the journal Brain and Cognition also back up that suggestion, as well as stating that children seem to prefer to sleep on their mother's left side. Having children on your left side puts them closer to your heart, and many researchers suggest this helps to keep babies and children calm.
It also seems that it's not just humans who favor carrying their offspring on the left-hand side, either. Researchers from St Petersburg State University, Russia found that both populations of walruses and flying foxes also preferred to carry their offspring on their left-hand side.
If you find yourself preferring to hold your child on your left hip, or cradle them on your left side while feeding and cuddling, it may have more to do with science than you realized!