When do children start lying?
● Seminal work by Lewis (1989, 1993, 2000)
● Usually use a temptation resistance paradigm: protecting self - eating cake, pretending not to
have undertaken a forbidden act
● e.g. during the pandemic parents set a bowl of sweets in front of their child, told them not to
eat any, and left the room, while leaving their phone to record what happens
Replication of findings:
● Early work: Peskin (1992), Polak and Harris (1999), and Lewis et al. (2000)
● Behaviour of lying starts to develop in pre-school years
● There is a general agreement that around 50% of three year olds can lie, and that most four
year olds are able to tell a deliberate lie
Theory of mind
● Between 3 and 5 years, children develop knowledge and understanding of others’ minds, this
has been shown to link with the ability of deception
● Smarties experiment
Talwar and Lee (2002)
● examined lying behaviour in children between 3 and 7 years
● a temptation resistance paradigm was used in which children were left alone and a desirable
toy placed behind their back, the children were told not to peek at the toy
● Most children could not resist the temptation and peeked at the toy (80%)
● When the experimenter asked them whether they had peeked, about half of the 3 year olds
confessed to their transgression, whereas 95% of older children lied
● Naive adult evaluators (undergraduate students and parents) who watched video clips of the
children’s responses could not discriminate lie tellers fro truth tellers on the basis of their
non-verbal expressive behaviour
● Presentation mode of children was varied → The children were poor at semantic leakage
control and adults could correctly identify most of the lie-tellers based on their verbal
statements but not so goof when non-verbal cues were available
● The results regarding children’s verbal and nonverbal leakage control suggest that children
under 8 years of age are not fully skilled lie-tellers
All these temptation resistance studies are conducted in the lab
What are the problems?
● conducted in a lab, artificial → low ecological validity
● children might not be motivated to lie or tell the truth, don’t care much
● interviewers might not be very invested in interviewing, low stakes
What are the advantages?
● the studies are controlled
● Seminal work by Lewis (1989, 1993, 2000)
● Usually use a temptation resistance paradigm: protecting self - eating cake, pretending not to
have undertaken a forbidden act
● e.g. during the pandemic parents set a bowl of sweets in front of their child, told them not to
eat any, and left the room, while leaving their phone to record what happens
Replication of findings:
● Early work: Peskin (1992), Polak and Harris (1999), and Lewis et al. (2000)
● Behaviour of lying starts to develop in pre-school years
● There is a general agreement that around 50% of three year olds can lie, and that most four
year olds are able to tell a deliberate lie
Theory of mind
● Between 3 and 5 years, children develop knowledge and understanding of others’ minds, this
has been shown to link with the ability of deception
● Smarties experiment
Talwar and Lee (2002)
● examined lying behaviour in children between 3 and 7 years
● a temptation resistance paradigm was used in which children were left alone and a desirable
toy placed behind their back, the children were told not to peek at the toy
● Most children could not resist the temptation and peeked at the toy (80%)
● When the experimenter asked them whether they had peeked, about half of the 3 year olds
confessed to their transgression, whereas 95% of older children lied
● Naive adult evaluators (undergraduate students and parents) who watched video clips of the
children’s responses could not discriminate lie tellers fro truth tellers on the basis of their
non-verbal expressive behaviour
● Presentation mode of children was varied → The children were poor at semantic leakage
control and adults could correctly identify most of the lie-tellers based on their verbal
statements but not so goof when non-verbal cues were available
● The results regarding children’s verbal and nonverbal leakage control suggest that children
under 8 years of age are not fully skilled lie-tellers
All these temptation resistance studies are conducted in the lab
What are the problems?
● conducted in a lab, artificial → low ecological validity
● children might not be motivated to lie or tell the truth, don’t care much
● interviewers might not be very invested in interviewing, low stakes
What are the advantages?
● the studies are controlled
