In the United States, calls to lift the obligation to wear a mask at school have multiplied in recent weeks, including within the scientific community, at a time when the cases of Covid-19 are plunging.

Scientific studies have shown that masks do have an impact on children's ability to recognize faces and emotions.

As with adults, masks can also interfere with verbal communication.

But experts are divided on the long-term effects on their development.

Language

The first fear concerns the learning of language, which takes place in the first years of life.

Children learn to speak through social interactions, and in particular look at the mouths of adults in order to dissect the different phonemes.

This path being blocked, it seems logical to suppose a harmful effect.

"It's true, you look at faces when you learn to speak," Diane Paul, of the American Association of Speech-Language Pathologists (ASHA), told AFP.

"But it's not the only way."

Children also help themselves with their voices, movements, or even their eyes.

She notes that those with visual impairments also learn to speak well.

And that the masks are not worn permanently, for example at home.

A child wears a mask while waiting for a train at Hankou station in Wuhan, China, January 17, 2022 STR AFP

"At present, there is no study that has demonstrated the long-term impact of interactions between young children and masked adults on the development of speech", insists the specialist.

"But there are studies showing that children can tune into these other communication signals."

A 2021 study demonstrated that infants were able to recognize unique words through a mask, just as well as without.

But according to another, conducted in France, masks can interfere with learning to read in children in difficulty.

In general, research remains rare on the subject.

But "I really see no reason to panic," said Diane Paul.

The main US federal public health agency (CDC), states that "the limited data available does not provide clear evidence that masks harm the emotional and language development of children".

She thus recommends wearing a mask from the age of 2 – against 5 years for the World Health Organization.

Social connections

But among psychiatrists, the story is a little different.

“The emotional aspect is even more important,” judge Manfred Spitzer, also a specialist in cognitive neuroscience at the University of Ulm in Germany.

He notes that the first thing lost with a mask is the sight of a smile.

“In the educational context, there are a lot of implicit exchanges between teachers and children,” he explains to AFP.

"If you alter this communication, you are bound to lose teaching success."

Fears also relate to the ability to form social ties.

Numerous studies have shown that masks make it more difficult to identify faces and emotions, including – or even more – among the youngest.

But conclusions about the consequences differ.

A study of children aged 7 to 13, published in the journal PLOS One, confirmed that emotions (fear, sadness, anger) were less well identified when someone wore a mask -- but with similar results in comparison wearing sunglasses.

She thus considered "unlikely that the social interactions of children will be radically altered in their daily lives".

A mother talks to her son before entering class at an elementary school in Bogo, Cebu province in the Philippines on November 15, 2021 Cheryl Baldicantos AFP

But other work, published in Frontiers in Psychology, has shown that performance in identifying emotions drops significantly between ages 3 and 5.

Results suggesting, according to the authors, that the mask "could potentially" affect "social development and emotional reasoning".

So, should we panic?

"I think we should worry as a society, not that parents should worry about this all the time," said Carol Vidal, a psychiatrist at Johns Hopkins University.

She, who works in schools in the United States, is part of a group of scientists calling for the lifting of the compulsory mask at school, where its scrupulous wearing is complicated anyway.

“They are no longer necessary at this stage of the pandemic”, she judges with AFP, taking into account in particular the low risks incurred by children in the face of Covid-19, and the vaccines now available from 5 years old.

It's all about balancing the benefits and the risks, she stresses.

But those posed by the masks "may not be considerable in terms of immediate effects, but I think we should be careful."

© 2022 AFP