Why women tend to hold their babies on their left side
We're all just monkeys with more developed brains.
Evolution is a fascinating, and something that's informed a lot of what we do and who we are.
Goose bumps, male nipples, the grasp reflex in our hands - humans have a lot of evolutionary leftovers all over the body and science might just have pinpointed one more.
New research suggests that liwomen carry their babies on their left side to encourage emotional bonding.
Up to 85 per cent of mums instinctively cradle their babies to the left, previous studies have found.
Researchers at St Petersburg State University wanted to know whether this was apparent in other mammals as that would suggest that the instinct is a hangover from the days humans roamed among the animals.
They found that walruses and flying foxes are twice as likely to cradle their young to their left sides and that when separated from their mother's, the young were more likely to position themselves in the mother's left field of vision.
The researchers concluded that the reason for the left is because a mother responds best to a baby's actions, like crying, when cradling it.
The left side of the body is guided by the right hemisphere of the brain and is also the side that processes emotion.
It's thought that mums hold their babies to the left to engage the right side of their brain and encourage better emotional processing to respond best to the baby's behaviour.
The study was published in Royal Society: Biology Letters.