Children’s Trust in Adults’
Testimony
Paul L. Harris

Collaborators
• Fabrice Clément (University of Geneva)
• Melissa Koenig (University of Chicago)
• Marta Giménez (Open University, Spain)
• Francisco Pons (Aalborg University, Denmark)
• Elizabeth Meins (University of Durham)

Collaborators
• Elisabeth Pasquini (Harvard University)
• Rita Astuti (LSE, London)
• Suzanne Duke (Harvard University)
• Jessica Asscher (University of Amsterdam)
• Kathleen Corriveau (Harvard University)

Collaborators
• Rémi Torracinta (Cycle de Drize, Geneva)

Overview
• The scope of testimony
• The early development of selective trust
• Parallel testimony: The case of death
• Testimony and ontology

The Scope of Testimony:
Coady’s Parable
• “My first morning in Amsterdam I wake uncertain of the time and ring the hotel clerk to discover the hour, accepting the testimony of his voice...I read a paperback history book which contains all manner of factual claims that neither I nor the writer can support by personal observation or memory or by deduction from either: the deeds of a man called Napoleon Bonaparte...I reflect that on arriving at a strange city a day or so earlier, I had only the aircrew’s word that this was
Amsterdam...”

The development of trust and doubt
• When children are given information that they cannot check for themselves, do they accept information from any informant?
• Alternatively, do they select among informants?

The development of trust and doubt
• Do they keep track of an informant’s past reliability?
• Do they prefer information from reliable as opposed to unreliable informants?

Koenig, Clément & Harris (2004)
• 3- and 4-year-olds received:
• Familiarization trials
• Judgment trials
• Test trials

Koenig, Clément & Harris (2004)
• Familiarization trials: children observed two adults:
– a reliable adult who consistently named familiar objects accurately.
– an unreliable adult who consistently named objects inaccurately.

“That’s a
….ball”
“That’s a
…shoe”

Koenig, Clément & Harris (2004)
• Children then received Judgment Trials:
• Judgment Trials: “Did either of them say anything right/wrong? …Who?”

Koenig, Clément & Harris (2004)
• Children then received Test Trials:
• Test Trials: An unfamiliar object was introduced and each informant named it differently.

“That’s a wug”.
“That’s a dax”.

Koenig, Clément & Harris (2004)
• Children were asked: “What do you think it’s called?”

Koenig, Clément & Harris (2004)
• Children were divided into two groups:
– Judgment not perfect
– Judgment perfect

Koenig, Clément & Harris (2004)
• We then asked how these two groups performed on test trials.
• How often did they choose the more reliable informant?

Selection of more reliable informant on test trials by age and judgment
1
0.75
0.5
0.25
0
3 years 4 years
Judgment not perfect
Judgment perfect

Next Steps
• How long does selectivity last?
• Are preschoolers only sensitive to consistent accuracy versus consistent inaccuracy?
• Do preschoolers prefer familiar informants?
• Does attachment have an impact?

Corriveau & Harris (2006)
• Given that 3- and 4-year-olds are selective, how long does their selectivity last?
• Day 1: Familiarization + Judgment + Test trials
• One Day Later: Test Trials
• One Week Later: Test Trials

Selection of more reliable informant on test trials by time and judgment
1
0.75
0.5
0.25
0
Same day
After 1
Day
After 1
Week
Judgment not perfect
Judgment perfect

Pasquini et al. (2006)
• 3- and 4-year-olds again observed two adults:
– An adult who was more reliable over four trials
– An adult who was less reliable over four trials

Pasquini et al. (2006)
• 100% versus 0%
• 100% versus 25%
• 75% versus 0%
• 75% versus 0%
• 75% versus 25%

Pasquini et al., (2006)
1
0.5
0
100% vs.
0%
100% vs.
25%
75% vs.
0%
75% vs.
0%
75% vs
25%
3-year-olds
4-year-olds

Pasquini et al., (2006)
• 3-year-olds were above chance only when one informant was 100% correct. They were
‘unforgiving’ of even one error.
• 4-year-olds were systematically above chance on all conditions. Their trust was undermined more gradually.

Pasquini et al., (2006)
• 3-year-olds display an all-or-nothing response.
• 4-year-olds display a graded response.

All-or-nothing
• 3-year-olds

All-or nothing
• 3-year-olds

Graded
• 4-year-olds

Graded
• 4-year-olds

Graded
• 4-year-olds

Graded
• 4-year-olds

Corriveau et al. (2006)
• Do children trust familiar more than unfamiliar informants?
• 3- and 4-year-olds were given test trials with one familiar and one unfamiliar caregiver at Centers 1 and 2.
• Children were shown an unfamiliar object and each caregiver gave a different name.

“That’s a wug”.
“That’s a dax”.
Caregiver 1 Caregiver 2

Choice of informant by Age and
Caregiver at Center 1
1
0.75
0.5
0.25
0
Caregiver 1 Caregiver 2
3 Years
4 Years

Choice of informant by Age and
Caregiver at Center 2
1
0.75
3 Years
0.5
4 Years
0.25
0
Caregiver 1 Caregiver 2

Corriveau, Meins & Harris (in preparation)
• Children falling into four attachment groups groups (avoidant, secure, ambivalent and disorganized) were given test trials in which their mother and an unfamiliar experimenter gave different names for an unfamiliar object.

“That’s a wug”.
“That’s a dax”.
Mother Stranger

Choice of informant (mother versus stranger) by attachment status
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Avoidant Secure Ambivalent Disorganized
Mother
Stranger

Summary of early selective trust
• 3- and 4-year-olds monitor for accuracy and prefer reliable informants.
• They remember errors for at least one week.
• Whereas 3-year-olds display mistrust after a single error, 4-year-olds are more forgiving.
• 3- and 4-year-olds prefer familiar informants, unless they have an avoidant attachment.

The development of trust and doubt
• Children will regard many adults as trustworthy because:
• They will have made accurate claims
• They will be familiar to the child.
• Children will trust these adults – even when they cannot check their claims.

Parallel Testimony:
The Case of Death
• Standard developmental approach: children gradually consolidate a biological ‘theory’ of death as a terminal point for all processes.
• Yet most children probably receive two parallel accounts of death: a biological and a religious account.
• Do children assimilate both different accounts?

Harris & Giménez (2005)
• Spanish children aged 7 and 11 years were given two stories about the death of an elderly person:

Biological Story
• “In this picture you see Juan’s grandfather. At the end of his life Juan’s grandfather got very ill and died. He was taken to a hospital where they tried to help him he was too old and they could not cure him. The doctor came to talk to
Juan about what had happened. He said to
Juan: “You grandfather is dead now.”

Religious Story
• “In this picture you see Marta’s grandmother.
At the end of her life Marta’s grandmother got very ill and died. She was taken to a hospital where they tried to help her but she was too old and they could not cure her. The priest came to talk to Marta about what had happened. He said to Marta: “Your grandmother is with God now.”

Harris & Giménez (2005)
• After each story, children were asked questions about the bodily and mental functioning of the dead person:
• Example of question about bodily functioning: “Have his eyes stopped working?”
• Example of question about mental functioning: “Can he still see?”

Proportion of ‘does not work’ replies by Story and Process Type (Spain)
1
0.8
0.6
0.4
0.2
0
Body
Mind
Biological Religious

Harris & Giménez (2005)
• More ‘does not work’ judgments given:
– For body than for mind
– For biological story than for religious story

Harris & Giménez (2005)
• Having made a ‘does not work’ or ‘does work
‘judgment, children were asked for a justification.
• Children generally backed up a ‘does not work’ judgment with a biological justification
• They generally backed up a ‘does work’ judgment with a religious justification.

Harris & Giménez (2005)
• Biological:
– “He has been eaten by worms, he has no body.
He just has bones”
– “If he is dead, nothing can work.”
• Religious:
– “In heaven everything can work even if she is dead”
– “The soul keeps working.”

Astuti & Harris (in press)
• Are two conceptions of death also found in a non-Christian culture?
• Rita Astuti repeated the Spanish study with the Vezo people of Madagascar.
• The Vezo worship their ancestors - who may bring misfortune on the family if they are angry or displeased.

Biological Story
“This is the picture of a man called Rampy.
He worked very hard all the time. And one day when it was very hot, he had a serious malaria attack, and his body and head ached a lot. His children and wife took him to the hospital, where he was given four injections.
Nonetheless, after three days from the time he arrived at the hospital, he died.”

Religious Story
“This is the picture of a man called Rapeto. He had many children and grandchildren. On the day when he died, many of his grandchildren were with him in his house. And now that he is dead, he is often in the dreams of his grandchildren. Rapeto’s family has built the cross for him, and his children and grandchildren are happy because the work for his tomb has been completed well.”

Proportion of ‘does not work’ replies by Story and Process Type
1
0.8
0.6
0.4
0.2
0
Body
Mind
Biological Religious

Proportion of participants in four categories:
Biological story
100
80
60
40
20
0
Total Cessation
Body>Mind
Body=Mind
Body<Mind

Proportion of participants in four categories:
Religious story
100
80
60
40
20
0
Total Cessation
Body>Mind
Body=Mind
Body<Mind

Astuti & Harris (in press)
• A similar pattern to Spain:
• More ‘does not work’ judgments given:
– For body than for mind
– For biological story than for religious story
– Two co-existing conceptions of death

Harris et al. (in preparation)
• Are these two conceptions universal?
– Harvard Student Believers
– Believers at a Catholic College
– Harvard Student Non-Believers

Number of ‘does not work’ judgments by process and group
6
3
2
5
4
1
0
Body
Mind
Harvard
Believers
Catholic
Believers
Harvard Non-
Believers

Summary
• Children and adults typically display two different conceptions of death: A biological conception and a religious conception.
• The religious conception may be parasitic on the consolidation of the biological conception.
• Most people display no cognitive tension between the two conceptions.
• Only non-believers seek to reconcile them.

Testimony and Ontology:
• In making ontological judgments children might adopt:
• An empirical strategy – “What exists is what I have observed or could observe.”
• A strategy based on testimony – “What exists is what I have been told about.”

Harris, Pasquini, Duke, Asscher
& Pons (2006)
• 4-5-year-olds and 7-8-year-olds were asked about three different types of entity:
• “Impossible” entities (e.g., Flying Pigs, Barking Cats)
• “Real” entities (e.g. Rabbits, Giraffes)
• “Scientific” entities: (e.g., Germs, Oxygen)

Harris et al. (2006)
• Children were asked:
– “Are there really _____?”

3
2.5
2
1.5
1
0.5
0
Predicted number of ‘yes’ responses to existence question: Empirical Strategy
Impossible
Real
Scientific

Predicted number of ‘yes’ responses to existence question: Testimony Strategy
3
2.5
2
1.5
1
0.5
0
Impossible
Real
Scientific

Actual number of ‘yes’ responses to existence question
3
2.5
2
1.5
1
0.5
0
4-5 Years 7-8 Years
Impossible
Real
Scientific

Do children differentiate among unobservables?
• Children accept scientific claims about the role of the brain.
• Children accept religious claims about the afterlife.
• Do children differentiate among such claims? Do they have equal confidence in every type of unobservable?

Harris et al. (2006): Experiment 2
• All unobservables are equal:
Mermaids = God = Germs
• Some unobservables are fictional; others
(special beings + scientific entities) do exist:
Mermaids < God = Germs
• Some unobservables are fictional; some special beings probably exist; some scientific entities definitely exist:
Mermaids < God < Germs

Experiment 2
• 5-6-year-olds were asked about three different types of unobservable entity:
• “Non-endorsed” entities (e.g., Mermaids, Ghosts)
• “Endorsed” entities: (e.g., God, Tooth Fairy)
• “Scientific” entities: (e.g., Germs, Oxygen)

Experiment 2
• Children were asked:
• Existence : “Are there really _____?”
• Confidence : “Are you very sure about that or not very sure?”

Experiment 2: Mean Number of
‘Yes’ Judgments
3
2.5
2
1.5
1
0.5
0
Mermaids God Germs
Existence
Confidence

Children’s justifications for
‘existence’ judgments
• Encounter (or Lack of Encounter) : “I saw them at the zoo” or “My uncle has one” or “I’ve never seen one”
• Source
: “Because I know that – my mum and dad told me that” or “I learnt that at school”
• Generalization
: “Because animals can have germs”
(non-causal) or “They give (you) diseases” (causal)

Experiment 2: Justifications
2.5
2
1.5
1
0.5
0
Mermaids God Germs
Encounter
Source
Generalization

Experiment 2: Conclusions
• Children differentiate sharply between
Mermaids on the one hand and God +
Germs on the other.
• They differentiate both for judgments and justifications.

Experiment 2: Conclusions
• In many ways, children conceptualize
‘endorsed’ special beings such as God and
‘scientific’ entities such as germs similarly.
– They often judge that each type of entity exists
– They often express confidence in that judgment
– They often justify their belief by offering generalizations – and by invoking a causal sequence

Experiment 2: Conclusions
• Yet children are also beginning to differentiate between
‘scientific’ and ‘endorsed’ special beings. Children’s judgment about the two types differ. Even if their pattern of justification is similar,
– They more often judge that ‘scientific’ entities exist
– They express more confidence in their judgment about
‘scientific’ entities

Summarizing:
Mermaids << God < Germs

Abarbanell (2006)
• interviewed children aged 10-13 years of the Tseltal-speaking Mayan community of
Tenejapa, Mexico.

Abarbanell (2006)
• impossible (e.g., flying pigs, barking cats)
• real (e.g., squirrels, chickens)
• scientific (e.g., germs, oxygen)
• endorsed (e.g., ch'ulelal, ijk'al )

Abarbanell (2006)
• Dead souls (ch’ulelal ) – the spirits or souls of the dead; a visit from the ch’ulelal can cause illness.
• Cave spirits (ijk’al) – small, black, cavedwelling creatures that allegedly assault people at night.

Abarbanell (2006)
3
2.5
2
1.5
1
0.5
0
10-13 years
Flying pigs
Dead
Souls
Chickens Germs

Summarizing:
Flying Pigs < Dead Souls < Germs = Chickens

Explanations:
• Why are children more confident about germs than God (or dead souls)?
• Three explanations:
– Children are scientists – they assess claims for their causal plausibility
– Children are sociologists – they sample public opinion
– Children are linguists – they are sensitive to the pattern of speech acts

Children are scientists – they assess claims for their causal plausibility
• Children grasp that special beings, unlike scientific entities, have extraordinary properties, e.g., God is omniscient (Barrett, Richert & Driesenga, 2001); immortal (Giménez, Guerrero & Harris, 2005); and the
Creator of species (Evans, 2000).
• Arguably, these extraordinary properties lead children to wonder if special beings really do exist.

Children are sociologists – they sample public opinion
• Children might keep track of the degree of consensus surrounding a given entity
• They notice that everyone believes in germs but some people doubt the existence of special beings
• Louis: “Some families believe in God”

Children are linguists – they are sensitive to the pattern of speech acts
• Affirmation versus presupposition

Belief in special beings is often affirmed - rather than presupposed
• “I believe in God” • “Don’t touch that – it has germs” vs. “I believe in germs” (?)
• “There really is a
Tooth fairy”
• “You need oxygen to breath” vs. “There really is oxygen” (?)

How to test?
• Suppose that in a traditional, isolated community, children encounter unanimity rather than diversity of opinion about special beings and they encounter presuppositions
(rather than assertions of faith) about such beings

Predictions
• Children are scientists:
– Ancestors < Chickens
• Children are sociologists:
– Ancestors = Chickens
• Children are linguists
– Ancestors = Chickens

Ontology: Conclusions
• Children display no sharp discontinuity between the way they conceive of unobservable ‘scientific’ entities and the way they conceive of unobservable special beings, including God.
• Yet there are clear signs of a differentiation.
• How universal is that differentiation.?
• What drives it?

The Cautious Disciple?
• Preschool children are cautious about whose information they accept.
• Children - and most adults - are ‘disciples’; they believe not only in biological death but in an afterlife.
• Children accept the existence of scientific and religious entities that they cannot see.
• Yet they show some caution with respect to religious entities.