Children around the world stop believing in Santa Claus around the age of 8, according to an international survey which also showed that about 34 per cent of adults wished that they still believed in Father Christmas.
The study also shows the threat of being on Santa's naughty list does not work for many children, and many youngsters continue to pretend they believe in Father Christmas even when they know he does not exist.
Psychologist Professor Chris Boyle, from the University of Exeter in the UK, asked people around the world to tell him how they changed their minds about Santa, and if learning that he is not quite as he seems had affected their trust in their parents.
Boyle received 1,200 responses from all around the world to his The Exeter Santa Survey, the only international study of its kind, mainly from adults reflecting on their childhood memories.
The findings show that 34 per cent of people wished that they still believed in Santa with 50 per cent quite content that they no longer believe.
The average age when children stopped believing in Father Christmas was 8, according to the study.
About 65 per cent of people had played along with the Santa myth, as children, even though they knew it was not true.
A third of respondents said they had been upset when they discovered Father Christmas was not real, while 15 per cent had felt betrayed by their parents and ten per cent were angry.
Around 56 per cent of respondents said their trust in adults hadn't been affected by their belief in Father Christmas, while 30 per cent said it had.
A total of 31 per cent of parents said they had denied that Santa is not true when directly asked by their child, while 40 per cent had not denied it if they are asked directly.
About 72 per cent of parents are quite happy telling their children about Santa and playing along with the myth, with the rest choosing not to.
"During the last two years I have been overwhelmed by people getting in touch to say they were affected by the lack of trust involved when they discovered Santa wasn't real," said Boyle.
"It has been fascinating to hear why they started to believe he is fictional. The main cause is either the accidental or deliberate actions of parents, but some children started to piece together the truth themselves as they became older," he said.
"As much as this research has a light-hearted element, the responses do show a sense of disappointment and also amusement about having been lied to," he added.