Why we usually carry babies on the left

I'm one of them. You probably are too. Duchess Catherine as well. And even the Virgin Mary. What we all have in common: The majority of us carry our baby in our left arm.

The phenomenon has already been proven in several studies in the past. And interestingly, the left preference can be found in all cultures and ethnic groups - across centuries. A Norwegian scientist from the University of Science and Technology in Trondheim has now analysed the available data and meta-studies for a review. This has been published in the journal "Infancy".

Heart and sensory perception speak in favour of the left

Audrey van der Meer has summarised several reasons for the left preference. One of them: the heart. Because it is located on the left side, the baby can hear its parents' heartbeat better when lying on the left. However, this theory could not be confirmed in subsequent studies.

Another theory states that the preference has to do with sensory perception: Parents intuitively place the child on the left side because they want to keep it in their left field of vision. The left eye and left ear receive information about the child's emotional state, which is then sent to the right hemisphere of the brain and interpreted there.

Strong arm should remain free

In the eyes of Van der Meer, however, a simple reason is probably the most plausible: the phenomenon is closely linked to the arm that we use most often. Parents keep their "preferred arm" free in order to remain flexible - for example, to put a dummy in their mouth, stroke their child or do other things. And 9 out of 10 people in the world are right-handed, the scientist states in her study.

Van der Meer mentions Prince William in this context. There are many pictures of the royal in which he is cradling his baby in the crook of his right arm, Van der Meer told "Norwegian SciTech News. "He is left-handed."

The left-hand preference only applies to babies. The bigger and heavier children get, the more we tend to carry them on the right side. In our dominant and stronger arm.