17:21 10 January 2017
Researchers based in Russia, the US and Australia claimed to have solved the mystery of why mothers tend to cradle newborn babies on the left. They explained that “positional bias”, which is also found in other animals, activates the right hemisphere of the brain that helps in communication and bonding.
Dr Yegor Malashichev of Saint Petersburg State University, said the position, which is also seen in kangaroos, horses, walruses and orcas, among others, helped in survival and social bonding.
"If there is no eye contact, or it is wrong, there is no activation of the right hemisphere of the infant... the right hemisphere is responsible for social interactions,"
"All the [11] species we studied demonstrated the lateral bias.
"We suggest that this bias is even more widespread and may be a characteristic of all mammals, with few exceptions. " She added that the mechanism was likely to be “ancient and really basic.”
It has long been observed that humans and great apes tend to cradle their babies on the left and various explanations have already been proposed including allowing the mother to keep a hand free for other tasks.