Babies may develop a deep-seated of the dentist before they even grow their first teeth, scientists say. Picture: Ian Landsberg

London - If the thought of the dentist’s drill sets your teeth on edge, blame your mother.

Babies may develop a deep-seated of the dentist before they even grow their first teeth, scientists say.

They believe that fear can be passed between generations, with mother to child the primary route.

The tantalising idea comes from research into the “smell of fear”.

The US study showed that newborn rats learn what to fear by sniffing odours given off by their mothers.

The researchers believe something similar happens in people, with babies picking up on changes to their mother’s voice, face, movements or even their smell.

Jacek Debiec, a child and adolescent psychiatrist, began by teaching female rats to be scared of the smell of peppermint.

The rats were then mated and the minty smell released again, this time in the presence of the mothers and their newborn pups.

The babies quickly picked up on their mother’s fear – and even when ‘teenagers’ went out of their way to avoid the smell of mint, the journal Proceedings of the National Academy of Sciences report.

The newborns were deaf, blind and could barely move, so it is thought they picked up on a specific smell that their mothers gave off when scared.

The finding is important, because very young rats are usually unable to learn about dangers.

Dr Debiec, of New York University School of Medicine, said: “During the early days of an infant rat's life they are immune to learning information about environmental dangers.

“But if their mother is the source of threat information we have shown they can learn from her and produce lasting memories.

“Our research demonstrates infants can learn from maternal expression of fear, very early in life. Before they can even make their own experiences they basically acquire their mothers' experiences.

“Most importantly these maternally-transmitted memories are long-lived, whereas other types of infant learning if not repeated rapidly perish.”

He believes that children learn some of their mother’s fears – with some being passed on very early in life.

Examples may include fear of the dentist, fear of violence and extreme shyness.

A father may also transmit his fears, if he is the parent providing most of the care.

Some other fears – such as fear of spiders – are hardwired into the human brain but can be magnified by a parent’s actions, said Dr Debiec.

His research on rats could lead to a way of stopping crippling fears from being passed on. It could also help protect children from being affected by their mother’s depression or anxiety about something that happened long before they were born. - Daily Mail