Holding a child on the left hand-side is the most common position adopted by a mother with her child. The research that links this with closer bonding suggests this leads to most women connecting most closely with their child. While the left hand preference has been known for several decades (with 8 out of 10 women typically adopting this position), psychologists have not known why. A new research project, from the Department of Vertebrate Zoology, Saint Petersburg State University, aims to address this.
Left-side bias or left-cradling bias is most common, the study has found, because it encourages the right side of the brain to process emotions and take in information from the world around us. This preference is not only found with humans, but also with many other mammals, especially the great apes.
According to Refinery29, this comes down to the two brain hemispheres carrying out different functions. The left hemisphere controls the right side of the body and vice versa. When a woman holds her baby on the left-hand side, this allows her to process aspects like emotion, crying, and facial recognition with the right side of her brains. These factors help to cement mother-child bonding since the right side of the brain aids in the deciphering and dissecting of what a person sees.
The findings are published in the journal Nature Ecology and Evolution, and it is called “Lateralization of mother–infant interactions in a diverse range of mammal species.”
