For children with a fertile imagination, a make-believe friend is a constant source of comfort and companionship.
But for their parents - who believe children should talk to real friends rather than invisible ones - it can be a cause for concern.
It seems, though, that they are worrying for no reason, as a study shows that imaginary friends can have a positive effect on children.
Such companions - whether a superhero or a fire-breathing dragon - are the sign of an imaginative child, and offer their creators a friend to confide in as well as a boost to their self-esteem.
Research at the Institute of Education in London found that made-up friends enhanced children's creativity, making them more confident and articulate.
Famous invisible friends include Soren Lorenson, the confidant of the character Lola in the hit children's TV series Charlie and Lola.
"Imaginative children will create imaginary friends," said Karen Majors, an educational psychologist who carried out the research. "Companionship is a big part of it. They can be a way of boosting self-confidence."
Parents should not worry even if their child creates a number of companions, according to Miss Majors, who says it's a perfectly normal habit.
She added: "Parents sometimes think, 'Is this healthy and how long should it go on for?' But it is a normal phenomenon for normal children. And it's very healthy."
Characters from fiction such as Peter Pan and Harry Potter figure frequently as invisible friends.
Girls tend to adopt younger companions, while boys tend to opt for older, more heroic characters. The study found that an only child or one with a large age gap from its siblings is most likely to create imaginary friends.
It is also common for such friends to appear when a brother or sister is born.
Victims of bullying may dream up companions for support and to help cope with the stress of their situation.
But in many cases, it is simply wish fulfilment for a child denied a much-wanted pet or other object of desire. "I interviewed one little girl who had a pony called Minty for several years," said Miss Majors. "Of course Minty did not really exist."
Earlier research by psychologist Anna Toby, who followed 20 children between the ages of four and eight with invisible pets and fabricated parents, found that an active imagination should be welcomed.
Her study found that "children who have imaginary companions have more advanced communication skills".
Researchers have estimated that as many as 65 per cent of children have had an imaginary companion at some point.
But it is not just children who converse with invisible companions. Explorer Dave Mill created his imaginary friend Nobody at the age of 34 as a survival mechanism during a solo walk to the North Pole.
Imaginary: Lola, from the hit TV series Charlie and Lola, has a pretend friend called Soren
By NICK McDERMOTT
But for their parents - who believe children should talk to real friends rather than invisible ones - it can be a cause for concern.
It seems, though, that they are worrying for no reason, as a study shows that imaginary friends can have a positive effect on children.
Such companions - whether a superhero or a fire-breathing dragon - are the sign of an imaginative child, and offer their creators a friend to confide in as well as a boost to their self-esteem.
Research at the Institute of Education in London found that made-up friends enhanced children's creativity, making them more confident and articulate.
Famous invisible friends include Soren Lorenson, the confidant of the character Lola in the hit children's TV series Charlie and Lola.
"Imaginative children will create imaginary friends," said Karen Majors, an educational psychologist who carried out the research. "Companionship is a big part of it. They can be a way of boosting self-confidence."
Parents should not worry even if their child creates a number of companions, according to Miss Majors, who says it's a perfectly normal habit.
She added: "Parents sometimes think, 'Is this healthy and how long should it go on for?' But it is a normal phenomenon for normal children. And it's very healthy."
Characters from fiction such as Peter Pan and Harry Potter figure frequently as invisible friends.
Girls tend to adopt younger companions, while boys tend to opt for older, more heroic characters. The study found that an only child or one with a large age gap from its siblings is most likely to create imaginary friends.
It is also common for such friends to appear when a brother or sister is born.
Victims of bullying may dream up companions for support and to help cope with the stress of their situation.
But in many cases, it is simply wish fulfilment for a child denied a much-wanted pet or other object of desire. "I interviewed one little girl who had a pony called Minty for several years," said Miss Majors. "Of course Minty did not really exist."
Earlier research by psychologist Anna Toby, who followed 20 children between the ages of four and eight with invisible pets and fabricated parents, found that an active imagination should be welcomed.
Her study found that "children who have imaginary companions have more advanced communication skills".
Researchers have estimated that as many as 65 per cent of children have had an imaginary companion at some point.
But it is not just children who converse with invisible companions. Explorer Dave Mill created his imaginary friend Nobody at the age of 34 as a survival mechanism during a solo walk to the North Pole.
Imaginary: Lola, from the hit TV series Charlie and Lola, has a pretend friend called Soren
By NICK McDERMOTT
