Olivia Beck "preferred her own company" and played alone in the corner when she started school. At first, her mother Tori thought her daughter was "just a little bit too advanced" for her age.
When Olivia continued to say she found it "more fun" to read her book at break times than to join in, Tori accepted it. But, a few years later, she had a wake-up call when her daughter's Year 3 form teacher told her that Olivia had been giving some of her classmates her pocket money to let them include her in their games.
Today, her only child's lack of friends is the main worry for this part-time lecturer from Hertfordshire. "I thought she would find a friend to click with eventually," says Tori, 46. "But it's heart-breaking to see her have no one to go on a play-date with and not get invited to parties."
Every parent wants their child to have friends. And however reluctant they may be to admit it, every child wants the same. When the Children's Society asked children what made their childhood happy, friendship was the factor they mentioned most.
According to new research, whether their children makes friends is also the top worry for parents, with a third expressing concern about it as the new school year nears.
Until now, it's been assumed that making friends is just something youngsters have to learn to do by themselves. However, a ground-breaking approach from the United States is treating social difficulties in the playground in the same way as any other learning difficulty. Just as some children have trouble making sense of the letters they see on the page, it is thought that less popular children have a sort of "social dyslexia" - a difficulty understanding and interpreting social cues. And the new approach is not just for children on the autistic spectrum - it is also designed to help youngsters who don't easily "get" the complex rules of friendship.
According to Michelle Garcia Winner, the California-based speech and language pathologist who helped pioneer the new thinking, the reason some youngsters are left out is because they come into the world with fewer social skills than others. They may also become anxious and frustrated, making the issue worse. While it takes the average youngster less than a second to read social cues, Winner says it may take children with social learning challenges a little longer, making it difficult for them to join in or say the right thing at the right time.
"Considering that 75 per cent of communication is facial expression and body language, stance, volume and tone of voice - and 25 per cent is language - being sluggish at interpreting these cues can leave them at a serious disadvantage," she says.
According to a study by Atlanta's Emory University, 10 per cent of children have one or more problems in sending or understanding non-verbal signals (known as dyssemia). In a class of 30, that means up to three children will be left on the sidelines. They may be viewed as "weird" by their classmates, a label that can be difficult to shed.
Winner says: "It's heart-wrenching to see the sadness caused by a child's rejection. They may look stoic at school, but over time it can build into depression and anxiety. The goal is not to have these kids start to be considered 'cool', but just to help them feel included."
Parent educator and author Noel Janis-Norton is the first to teach "social learning" in Britain at the Calmer, Easier, Happier Parenting Centre in North London. She believes children shouldn't be left to struggle alone. "Many of these children can be spared this suffering. It's never too early or too late to start teaching social skills.
"Luckily, the brain is very malleable. Sometimes it's as simple as teaching a child the best way to use eye contact or what body language to use. For example, in the playground many of these children stand on the fringes of games or tend to look away from the group they want to be part of, instead of looking interested. Teaching children to turn their body and shoulders towards the group and smile can often be enough to let the other children know that they want to be part of it."
However, psychologist Emma Citron believes it would help if all children were taught more about friendship, because now they have to learn to deal with rejection and exclusion at an earlier age, thanks to social media. "It's true that some children pick up social skills just like anything else, like spelling. But some need to have it unpacked and explained in order for them to get it. I would love to see more friendship education in schools."
It is also the case that as digital friendships develop online, some see less need to develop "real-life" friendships. This means that a socially awkward child, who might find it easier to make online friends, where the rules around social cues are different, may further retreat into themselves.
Yet, according to child development experts, this could be putting them at a disadvantage in the wider world, where emotional intelligence is increasingly valued and can be a key indicator of future success. Helping children develop their emotional intelligence through friendship, they argue, is as crucial as teaching them reading, writing and arithmetic.
Dr David Whitebread, director of Cambridge University's Centre for Research on Play in Education, Development and Learning, says: "Rough-and-tumble with friends creates strong emotional bonds and expressive awareness. Through this, children learn to be sensitive and establish their limits."
For Olivia's mother, the idea that she could be "taught to have friends" was a revelation, because she thought it was supposed to happen naturally.
"I found the possibility that other children did not like my daughter so painful, I just hoped the situation would magically correct itself. Now, instead of feeling powerless, I can finally do something and she is learning a skill that I used to think it was impossible to teach - how to be accepted."
What you can do to help your child
• Explain that making friends is a skill. In the same way that they can be smart at English or maths, they can learn "social smarts", which can get better with practice.
• Decode the use of body language. Tell them to turn the front of their body towards a group - and maintain the right distance - to let others know they want to join a game.
Explain that if they don't look at faces, other children will think they are not being friendly.
• Train them to be aware. Use films or TV programmes to help children guess what on-screen characters will do next, based on their facial expressions and body language.
• Talk about friendship. The shrinking of today's playtime, excessive after-school activities and screen time are two factors that mean many children are missing out on "friendship practice". In response, Becky Goddard-Hill, a trained psychotherapist, created Fink Friendship cards (finkcards.co.uk). Other resources include The Social Detective app, which uses real-life video clips to help children practise reading social cues and judge how to respond, available at socialthinking.com