Look to the left

Cradling a baby that way better for bonding, study finds

Mothers should carry their babies on their left-hand side because it creates a natural social connection, a study suggests.

Previous research has shown that up to 85 per cent of women will naturally cradle an infant to the left. Russian scientists were keen to find out whether the same pattern was present in other mammals, which would suggest it was a behaviour that evolved millions of years ago to aid bonding.

They studied populations of walruses and flying foxes. They found they were more than twice as likely to carry their offspring on the lefthand side.

Experts say left cradling is the best way for a mother to notice and respond to a baby’s behaviour, such as crying or laughter. In that position, important cues are directed to the right side of the mother’s brain, the hemisphere used for emotional processing. So cradling on the left gives the mother a faster way to pick up her baby’s requirements.

“Our results show that the left-sided positional bias is not a unique to primate evolution,” said Andrey Giljov of St. Petersburg State University, who participated in the study. “This consistent pattern may have emerged owing to mutual perceptual benefits resulting from enhanced social processing by the right hemisphere.”

Some parenting experts also believe that keeping a baby’s head close to the mother’s heart helps naturally soothe the child, who remembers the sound from being in the womb. Others claim the bias is based on handedness, with lefthanded women saying they prefer to hold their infants in their stronger left arm and right-handers arguing it keeps their dominant hand free to attend to the child.

The research was published in Royal Society: Biology Letters.