British Journal of Developmental Psychology (2001), 19, 413–432 Printed in Great Britain
# 2001 The British Psychological Society
413
Actions really do speak louder than words—but
only implicitly: Young children’s understanding
of false belief in action
Wendy A. Garnham
Laboratory of Experimental Psychology, University of Sussex, UK
Josef Perner*
Department of Psychology, University of Salzburg, Austria
Children show understanding of a mistaken story character’s actions in their visualorienting responses before they show this in their answers to test questions.
Clements and Perner (1994) interpreted the visual responses as reflecting implicit
understanding (implicit-knowledg e hypothesis). The present study explores three
possible ways of saving the hypothesis that different bodies of exclusively explicit
knowledge are involved (explicit-knowledge-onl y hypothesis): the lack-of-confidence hypothesis asserts that children are just not confident of the novel but correct
answer and the misinterpretatio n hypothesis claims that children are simply
misinterpretin g the test question. The temporal stacking hypothesis assumes that
children consider first the novel idea that the protagonist will go where he or she
thinks the object is and then they consider the more established idea that the
protagonist will go where the object really is. It explains the original finding by
assuming that visual responses are governed by the earlier and the verbal answers by
the later considered idea. The results offered little support for the first two of these
attempts to save the explicit-knowledge-only hypothesis. Although parts of the
results are compatible with the temporal stacking hypothesis, the overall pattern of
results is not. Rather, it is very similar to findings from implicit visual perception,
where people experience a lack of conscious awareness. This similarity reinforces the
original interpretation of a dissociation between implicit and explicit understanding
of belief-based action.
The development of children’s theory of mind makes an important step with the
understanding of misinformation, in particular the understandin g of false belief.
Although different tasks for assessing this understandin g have some effect, overall the
age trend is quite robust, located between 3 and 5 years (Wellman, Cross, & Watson,
2001). However, Clements and Perner (1994) reported a substantially earlier, but
implicit, understandin g of false belief. Such precocious, implicit understandin g has also
* Requests for reprints should be addressed to Dr. Josef Perner, Institute für Psychologie, University
Salzburg, Hellbrunnerstrass e 34, A-5020 Salzburg, Austria.
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Wendy A. Garnham and Josef Perner
been reported in other domains of knowledge. Children display a more advanced
understandin g of Piagetian quantity conservation (Church & Goldin-Meadow, 1986)
and arithmetic equations (Perry, Church, & Goldin-Meadow, 1988) in their spontaneous
manual gestures before they show this understandin g in their answers to experimenters ’
questions.
The finding by Clements and Perner (1994) is based on the typical false belief test
(Wimmer & Perner, 1983). They enacted a story about a protagonist (Sam the Mouse)
that was ignorant of the transfer of an object (piece of cheese) from one box (A) to
another box (B). The important change from the traditional story was that at the critical
moment, the protagonist was behind the scenes and would reappear either from hole A
when retrieving something from box A or from hole B when retrieving an object from
box B. When asked to predict where the mistaken protagonist would look for his cheese,
most 3-year-olds answered wrongly with location B (where the cheese actually was), but
most of them (over 70%) looked in expectation to location A (where the protagonist
thought the cheese was). In a true belief control condition, where the protagonist had
witnessed the transfer from A to B, these children did not look to A, which reaffirms
that their looking to A in the false belief condition expresses some understandin g that
the mistaken protagonist will reappear at location A.
This precocious understandin g has been termed ‘implicit’ with some justification . In
memory research and subliminal perception, where the distinction between implicit and
explicit knowledge plays an increasingl y important role, one criterion for implicit
knowledge is that it shows up on an indirect test but not on a direct test (e.g. Reingold
& Merikle, 1993). A direct test is one in which the test instructions or questions refer to
the knowledge under consideration, as in the case of the experimenter’s question about
where the protagonist will look for the cheese. An indirect test is one in which no such
reference is made, and the participants’ behaviour just happens to show the existence of
such knowledge, as in the case of children’s spontaneous visual orienting responses in the
false belief test or their accompanying manual gestures in the Piagetian conservation
tests or arithmetic problems.
However, one aspect of implicit knowledge is its lack of access for conscious
awareness, which is considered to be central in memory research (Schacter, 1987) as well
as in implicit learning (Reber, 1993). In research with adults, lack of conscious access
can be validated (to some degree) directly through participants ’ reports, but for research
with 3-to 5-year-old children, any requirement to elicit such direct confirmation
provides an insurmountable hurdle. Therefore, we can only hope to establish the
implicit nature of this precocious knowledge indirectly by following two strategies. The
first is to see whether the knowledge underlying anticipator y looking behaves like
implicit knowledge in the adult literature (the implicit-knowledg e hypothesis). The
other is to rule out with new test conditions different attempts to explain the data by
assuming that only explicit knowledge is involved (explicit-knowledge-onl y hypothesis).
Two experiments were designed to test three fairly plausible attempts to save the
explicit-knowledge-onl y hypothesis. The pattern of results favours the implicitknowledge hypothesis over these attempts. Moreover, the results also resemble the
pattern of how implicit knowledge is used in contrast to explicit, conscious knowledge
False belief in action
415
in experiments with adult participants, which strengthens the impression that children’s
precocious understandin g of belief-based action is implicit in nature.
EXPERIMENT 1
The main objective of this experiment is to test the implicit-knowledg e hypothesis
against the possibility that children entertain two coexisting but contradictory bodies of
explicit knowledge. Besides the old but wrong theory, they also entertain the new
correct understandin g but simply lack confidence in their new understandin g about
belief (lack-of-confidenc e hypothesis) that makes them reluctant to commit themselves
to the correct answer. Siegler (1994) has made a strong case that, in general, cognitive
development is not a case of abruptly exchanging one theory for another. Rather,
children entertain several, often incompatible solution strategies for a problem. Acredolo
and O’Connor (1991) have highlighte d that children often entertain ‘contradictory
notions’ and that at any particular point in time, the majority of what a child knows is
understood only partially and therefore with some degree of uncertainty.
Applied to the present case, this might mean that the correct but novel hypothesis
that the protagonist will go to the location where he thinks the object is, is held at the
beginning with little confidence . However, even a low confidence idea can affect looking
because looking does not commit the child to a judgment of where the person will go.
In contrast, where an answer to a question (predict-protagonis t question) requires
commitment, children may prefer to stick to the incorrect answer of referring to the
object’s current location because it conforms to the simpler and safer old theory that
people retrieve something from its actual location (Fodor, 1992; Harris, 1993; Mitchell,
1996; Robinson & Mitchell, 1995; Russell, Mauthner, Sharpe, & Tidswell, 1991;
Zaitchik, 1991). If the lack-of-confidenc e hypothesis is correct, then the superior visualorienting responses reported in Clements and Perner (1994) may not reflect the
existence of implicit knowledge, but instead explicit knowledge of low confidence .
To test lack of confidence as an explanatio n for the gap between knowledge revealed
by visual-orientin g responses and knowledge expressed by answers to questions, a new
mat-moving response measure is incorporated. The same false belief task is used as in
Clements and Perner (1994), but, instead of requiring the child to give an answer to a
test question, children have to move a small mat to catch the protagonist as he comes
down one of two slides in search of the desired object. If children are just not confident
of their novel hypothesis that the protagonist will search for the object in the empty
location where he thinks the object is, then they should be just as reluctant to commit
themselves to this hypothesis for their mat-moving response as for their answer to the
standard anticipated-actio n question. In fact, they might be even more reluctant to
commit themselves to that location in their mat-moving responses because a wrong
judgment has the serious consequence that the protagonist will hurt himself without a
mat in place to soften his arrival.
Whereas the lack-of-confidenc e hypothesis predicts that there should be no difference
in accuracy between mat-moving responses and answers to the predict-protagonis t
question, the literature on adults’ use of implicit knowledge suggests otherwise. It has
been shown that only explicit, conscious perception is subject to certain illusions. For
instance, Aglioti, DeSouza, and Goodale (1995) report that Titchener’s circle illusion
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Wendy A. Garnham and Josef Perner
can be so adjusted that an objectively (by about 3mm) smaller disk surrounded by small
circles looks as large as a larger disk surrounded by large circles. However, when asked
to grasp the disks, the anticipatory thumb-index finger span adjusts to the actual size
difference , which shows that there is implicit knowledge of the real size relations
available for action, but not for conscious judgment of the relative size of the disks.
Similar dissociation between conscious judgment and finger movement has been
reported on the induced Roelof’s effect, the illusory movement of a stationary dot
induced by the movement of the dot’s surroundings (Bridgeman, Gemmer, Forsman &
Huemer, 2000; Bridgeman, Kirch, & Sperling, 1981). Applied to our problem, these
results suggest that children’s precocious understandin g of false belief might be
available for their mat-moving action before it is available for their explicit (conscious)
judgment of where the protagonist will reappear.
Method
Participants
Forty-nine children aged 2;5 to 4;7 from four playgroups in a predominantly middle-class area of
Brighton and Hove took part in this study. All children had English as their first language. Two children
were excluded from this study as they both refused to sit long enough to finish the first story. Both of
these children were aged below 2;7. Thus, the results of 47 children (21 boys and 26 girls) with a mean
age of 3;3, were analysed.
Materials
Each child was seated at a table on which a large 50 cm (length) 6 20 cm (height) 6 20 cm (width)
three-dimensiona l model was displayed. This model, made of card, depicted the following scene. A 17 cm
(height) 6 10 cm (width) flight of steps separated two playground areas. At the foot of the steps, there
was a 10 cm 6 8 cm brown mat (cut from a square of carpet). The steps were bordered by two 10 cm 6
20 cm 6 20 cm walls, each of which had a small doorway leading into one of the two playground areas.
The steps led to a doorway at the top of the model, which in turn led to the top of the slides. Each
slide was situated in one of two playground areas and protruded from a 5 cm 6 3 cm opening in the
back wall. One of the slides was coloured red, and one was coloured blue. A small box, 3 cm 6 3 cm, was
positioned 2 cm from the side of each slide. The box next to the red slide was coloured red, and the box
next to the blue slide was coloured blue.
Two playmobile figures, a boy and a girl, were used to enact the story events in this model. The object
to be transferred was either a small football or a bag of sweets. The small football was a black and white
ball of 1.5 cm diameter and for the bag of sweets, a small 2 cm 6 2 cm cube-shaped paper bag was
constructed and filled with three small sweet wrappers made from tissue paper.
A video camera was set up on the same side of the table as the experimenter. The camera was placed so
that each child was visible from the waist up with a clear view of the child’s face.
Design
Each child was tested in two sessions approximately seven days apart. In each session, each child was told
one false belief and one true belief (control) story. At the end of the narrative in one session, children were
asked the standard question as used in Clements and Perner (1994): ‘Where is Alan going to look?’ This
is referred to as the anticipate-protagonist condition. In the other session, at the end of the narrative,
children were simply instructed to move the mat to catch Alan as he came down one of the two slides:
‘Quick! Move the mat to catch Alan as he comes down the slide!’ This is referred to as the mat-moving
condition.
The following counterbalancing measures were made. For half of the children, the anticipateprotagonist condition was administered in the first session and the mat-moving condition in the second
False belief in action
417
session; for the other half, the conditions were administered in the reverse order. Within each session, the
order of presentatio n of the false and true belief stories was also counterbalanced. Whichever scenario was
used for the first story in one session, the other scenario was used for the first story in the second session.
For half of the participants, the boy character (Alan) was used as the main protagonist in the first story,
and the girl character (Rebecca) was used as the main protagonist in the second story. For the other half
of participants, the use of these characters as the main protagonist in each story was reversed. Within
each session, whichever character was used for one story in the first session, the other was used for the
first story in the second session. Whichever of the two objects was transferred in the first story, the other
object was transferred in the second story. Similarly, whichever object was transferred in the false belief
story in the first session, the other object was transferred in the false belief story in the second session.
Procedure
Each child was seated at a table in a quiet room separate from the main classroom/play area. In each
condition, children listened to two stories, one false belief and one true belief story. Each story began by
introducing the child to the story characters. Then, the experimenter narrated the story, enacting the
story events using the model in front of the child. In the false belief story, Alan plays with his football,
puts the ball into the red box and climbs up the stairs (behind the scene where he cannot see what
follows). Rebecca comes, moves his ball to the blue box in the other playground area, and leaves the
scene. Alan behind the scene expresses his desire to play ball again (at this point, a pause of 2–3 s was
made during which the child’s eye gaze direction was judged later on the video record), and the child was
asked to indicate on which slide Alan will come down (anticipate-protagonis t question) or was asked to
move the mat (mat-moving instructions). This was followed by three memory questions. The verbatim
narrative of one of the false belief stories can be found in the Appendix.
The corresponding true belief story differed from the false belief story only in that the protagonist
witnessed the transfer of the object from one location to the other. Specifically, the wording of Episode 2
(see Appendix) was changed so that Alan witnessed Rebecca moving the football from one location to the
other before climbing the steps to the top of the slide.
In each condition, the child’s looking behaviour was recorded on videotape. The video camera was
switched on before the experimenter had begun narrating the story and was left to record throughout the
duration of the story until the child had answered the three memory questions. To avoid the possibility
that the child was following the experimenter’s gaze, the experimenter, facing the child, looked at the
child at the critical point, immediately after the end of the narrative and before the child was asked the
anticipate-protagonis t question or was given the mat-moving instructions.
In the mat-moving condition, a familiarizatio n task was administered, before any true or false belief
stories had been heard. The aim of this task was to demonstrate the function of the mat in catching the
protagonist as he or she came down one of the slides so that the child understood what to do with the
mat in the test condition. In this familiarizatio n task, the protagonist put an object into one of the boxes,
climbed the slide and then declared his wish to retrieve the object. The object used was a small piece of
cardboard cut in the shape of a sweet wrapper coloured pink and blue. In this task, Episode 2 was
omitted so that there was no transfer of the object from one location to the other. This task was
administered twice to each child so that the protagonist retrieved the desired object from the red box
once and from the blue box once.
Scoring of responses. Post-hoc anticipatory looking responses were observed during the approximately 3s
pause between the end of the narrative and the start of the anticipate-protagonis t question. Raters were
asked to code each response as either A (looked longest at location A, where the protagonist thinks the
object is), B (looked longest at location B, where the object actually is) or N (either did not show a
preference for looking to A or B or not clear where the child was looking). For example, if a child spent
more time looking to location A than to any other place during the 3 s pause, this would be coded as an
A response. N codings were relatively rare; only 16% (30 of 188) of looking responses, 3% (three of 94)
of mat-moving responses and 8% (eight of 94) of verbal responses were coded as N by both raters.
To be interpreted as evidence of some understanding of belief, looking responses must be coded as A in
the false belief task (i.e. looked longest to the location where the protagonist mistakenly thinks the
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Wendy A. Garnham and Josef Perner
object is) and B in the true belief task (looked longest to where the protagonist thinks the object is,
which is also where the object actually is). This pattern is referred to as the AB pattern. However, it only
indicates an understanding of false belief if it occurs significantly more often than one would expect by
chance, that is the BA pattern, which is our best indicator of the average rate of chance looking patterns
because it has no other explanation. In contrast, the BB pattern might indicate fascination with location
B (because the object is actually there) and AA a fascinatio n with location A (because in both stories, the
object used to be there).
Besides the AB pattern, patterns NB and AN provide some, though weaker, evidence for
understanding (i.e. one could argue in the case of NB that the looking to B in the true belief control but
not looking to B in the false belief condition indicates some awareness of the protagonist’s not knowing
that the object is in B). Although we present the incidence of these patterns for interest, we nevertheless
rely primarily on the AB pattern as an indicator of understanding false belief.
The same scoring system was used for mat-moving and verbal responses also. For example, if children
moved the mat or verbally responded to location A in their answers, this was coded as an A response. If
they moved the mat or verbally responded to location B, this was coded as a B response.
For visual responses alone, inter-rater agreement was 87% (164 of 188, k = .79). For verbal and matmoving responses, inter-rater agreement was 98% (182 of 188, k = .92). Where disagreements did
occur, a conservative measure was used with responses being coded as N responses.
Results
The result of central importance concerns the frequency of the AB response pattern
(respond with A in false belief and with B in the true belief control story) in relation to
other response patterns and across the different experimental conditions. Table 1 shows
the relevant frequencies .
Table 1. Number of children showing a particular response pattern across the two
stories and the relative frequency of A:B responses for each story individually in
Experiment 1
Response pattern or story
Condition and response mode
Anticipate-protagonist
Mat-moving
Looking
Response pattern over false and true belief story
AB
20
BA
1
AN and NB
9
NA and BN
4
AA
5
BB
8
NN
0
Frequency of A:B responses
False belief story
29:14
True belief story
8:30
Answer
Looking
Move mat
10
1
3
1
1
29
2
18
4
11
4
1
8
1
20
0
3
0
0
24
0
11:31
2:42
25:15
6:31
21:24
0:46
As Table 1 shows for each condition and measure, the AB pattern is quite frequent,
whereas the BA pattern, which is our best indicator of mere random responding, is
False belief in action
419
extremely rare (and is shown only by children below the age of 2;11 except for the
looking behaviour by one child of 3;1). In each case, the Binomial Test shows the
difference to be highly significant (all ps < .01), which indicates that the AB pattern
expresses some understandin g of where the protagonist will reappear and is not the
result of pure random responding. Moreover, ignoring N responses, the lower panel of
Table 1 also shows that in the false belief story of the anticipate-protagonis t condition,
children look more often to A (29 children) than to B (14 children), and this differs
significantl y from chance (one sample w2 (1,43) = 5.24, p < .05; unless otherwise
indicated, all tests of significanc e are two-tailed).
Table 1 also shows that in the anticipate-protagonis t condition, the AB response
pattern is more frequent in children’s anticipatory looking (20 cases) than in their
answers to the test question (10 cases). This difference results from 14 children showing
the AB pattern in their looking but not in their answers, while only four showed it in
their answers but not in their looking (McNemar’s w2 (1,47) = 5.56, p < .02). This
replicates the original result reported by Clements and Perner (1994).
The important new result is that the AB pattern was also shown more often in
children’s mat moving (20 cases) than in their answers to the anticipate-protagonis t
question (10 cases). This difference is owing to the fact that 13 children showed the
pattern in their mat moving and not in their answers, whereas only three children
showed the opposite result (McNemar’s w2 (1,47) = 6.25, p < .02).
In fact, the incidence of the AB pattern in mat moving was as frequent as in children’s
looking in the anticipate-protagonis t condition (McNemar’s w2 (1,47) = .05, p > .90).
The fact that the AB pattern was slightly less frequent in children’s looking in the matmoving condition can be explained by the fact that the presence of the mat captured
children’s eye gaze, leading to more N scores (15%) than in the anticipate-protagonis t
condition (8%) where there was no mat.
Discussion
The finding that the AB pattern of responding was more frequent for mat-moving (and
about as frequent as AB looking responses in the anticipate-protagonis t condition) than
for answers to the anticipate-protagonis t question makes it difficult to save the explicitknowledge-only hypothesis with the lack-of-confidenc e explanation. If the low
frequency of AB responses for the anticipate-protagonis t question was because of
children’s low confidence in their explicit idea that the protagonist would reappear at A
in the false belief story, then their lack of confidence in this idea should also have made
them equally reluctant to move the mat to A. The data do not appear to support this
prediction.
In contrast, the data are compatible with the implicit-knowledg e hypothesis as
extrapolated from findings on perceptions of illusions in adults. It was found that
implicit knowledge is available not only for indirect tests (accompanyin g automatic
actions) but also for intentional action. For example, Bridgeman (1999; Bridgeman et
al., 2000) reports that people are quite accurate in moving their finger to a vanished
dot’s location, even when their conscious perception indicated that the dot had moved.
Analogously, children can use their precocious implicit knowledge not only in their
automatic visual orienting responses but also in their intentional action of moving the
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Wendy A. Garnham and Josef Perner
mat. Implicit knowledge is not available for declarativ e statements of what is the case
(Bridgeman et al., 1981). When asked to indicate the dot’s location in relation to a
reference grid, then answers are subject to the consciously perceived visual illusion.
Similarly, the children in the present study cannot use their precocious implicit
knowledge in response to the anticipate-protagonis t question to indicate what will be
the case.
Thus, our finding strengthens the case that the knowledge revealed in visualorienting and mat-moving responses that is not expressed in answers to questions is
‘implicit’ in nature and, therefore, different in nature from knowledge expressed in
answers to questions. However, this conclusion is still premature because, as mentioned
earlier, there are other plausible hypotheses to be ruled out, such as different versions of
the misinterpretation hypothesis. Perner, Leekam, and Wimmer (1987) have pointed out
that children might misinterpret the traditional test question ‘Where will the
protagonist look for the object?’ as ‘Where should the protagonist look for the object?’,
or that children may be keen to help the protagonist find the desired object and,
therefore, point to the location where the object is (and where the protagonist should
look). A related possibility is that children misunderstand the intended meaning (i.e.
where the protagonist will look first) as where will the protagonist look in the end and
find it (Siegal & Beattie, 1991). Surian and Leslie (1999) found that inserting ‘first’ in
the original test question used in the typical false belief story yields a very strong
increase in children’s correct responses at the age of 3‰–4 years, whereas Clements and
Perner (1994) reported a small non-significan t difference in the range of 2‰–4‰years
and Peterson and Siegal (1999) in deaf children. Others have added the ‘first’ routinely
(e.g. Joseph, 1998). The meta-analysis by Wellman et al. (2001) indicates that the
effectivenes s of this manipulatio n tends to be focused on the older end of the 2‰–6 year
spectrum. Still, we cannot assume that it could not be effective below the age of 3‰
years when the dissociation between looking at A, but answering with B to the question
tends to be largest.
Siegal (1996) pointed out another potential misinterpretation for the procedure used
by Clements and Perner (1994) who had added an ‘anticipation prompt’ to elicit more
looking to locations A and B before asking the test question. This prompt, ‘I wonder
where he is going to look!’, Siegal suggested, might be understood by some children as a
question to which they respond by looking to location A. The ensuing explicit test
question, ‘Where will he come out?’ is then misinterpreted by these children as a repeat
of the earlier question and taken as a reprimand of their earlier answer. These children
then switch to answering the test question with B after having looked at A. It is
important to note that this possibility does not apply to our present procedure and other
replications of the original study (e.g. by Garnham & Ruffman, 2001), where the use of
the anticipatio n prompt was dropped as it seems unnecessar y for eliciting looking to
location A or B.
In any case, if any one of the misinterpretation s outlined above does occur, then it
would explain why visual-orienting response and mat-moving response reveal an earlier
understandin g of false belief, simply because these responses are not hampered by the
same misinterpretations as the traditional test question (anticipate-protagonis t
question).
False belief in action
421
EXPERIMENT 2
The main purpose of this experiment is to rule out the misinterpretation hypothesis as
another way of saving the explicit-knowledge-onl y hypothesis in opposition to the
implicit-knowledg e hypothesis. To do this, a new reflect-mat-move condition was
introduced. Before children were allowed to move the mat, they had to answer the
reflective question: ‘Where are you going to move the mat?’ (reflect-mat-move
question). If the younger children do understand false belief in a way that is accessible
for answering questions but are trapped into giving wrong responses because they are
misinterpreting the standard anticipate-protagonis t question ‘Where will he look for the
object?’ as ‘Where should he look for the object?’, then these children can be expected to
give far more correct responses to this new reflect-mat-move question. The reason for
this is that even if they do gloss this question as ‘Where should you move the mat?’, that
would still let them give the same correct answer.
As mentioned, another possible misinterpretation is pragmatically to interpret the
test question as a request to help the ignorant protagonist find the object. By
hypothesis, even the youngest children are highly sensitive to the protagonist’s
ignorance and see the correction of his ignorance as the most relevant communicative act
in this situation and, therefore, answer the test question, which contains a reference to
the object, with the location where the object actually is. Although this pragmatic twist
to point out the actual location of the object is plausible for the traditional question that
contains a reference to the location of the object (‘Where will he look for the object?’), it
is much less plausible for the new reflect-mat-move question that does not even mention
the object.
Finally, a third way of misinterpreting the traditional test question is to change its
intended temporal reference (Siegal & Beattie, 1991). The assumption is that children
understand that the protagonist will keep looking and eventually will look where the
object is. By interpreting the intended meaning of the question as where the protagonist
will look right away, they may interpret it as meaning where the protagonist will
eventually look and answer with the object’s actual location. Again, although there is a
plausible possibility of reinterpreting the question about where the protagonist will
look for the object, it is not applicable to the reflect-mat-move question, ‘Where will
you move the mat?’, since the mat only needs to be moved once to catch the protagonist
coming down the slide. When he discovers that the object is not in the old location, the
protagonist will not use any slide again but walk over to the other box in order to look
in there.
In sum, if children’s answers to the new reflect-mat-move question are comparable to
their answers to the standard anticipate-protagonis t question but differ from their
visual-orientin g and mat-moving responses, then the different variants of the
misinterpretatio n hypothesis would seem to be unlikely explanations of the data. This
would erode another support for the explicit-knowledge-onl y hypothesis. In contrast,
such a result would be compatible with the implicit-knowledg e hypothesis because the
reflect-mat-move question asks for a declarativ e statement on an action for which the
precocious implicit knowledge would not be available, whereas the moving of the mat is
a mere action for which such precocious knowledge would be available.
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Another important objective of this study is to follow up an informal observation in
Experiment 1 concerning children’s timing of their responses. It was observed that some
children moved the mat virtually immediately after being given the instructions to do
so, while many others hesitated or needed further prompting before moving the mat,
and a few moved the mat back and forth between the locations before reaching a
decision.
This observation is important because it suggests a new test of differentiatin g the
implicit-knowledg e hypothesis from yet another way of saving the explicit-knowledge only hypothesis: temporal stacking (e.g. White, 1965). In hunting for a response, the
child encounters competing explicit hypotheses that are temporally stacked. If the child
tends to respond quickly the response is likely to be governed by an early hypothesis. If
the child hesitates the response is governed by a late occurring hypothesis. Assuming on
purely hypothetical grounds (there is no evidence that this really is the case) that the
novel hypothesis of the protagonist going to A is thought of first (perhaps because it is
novel and exciting), then children who respond fast are more likely to respond with A
than children who hesitate and, therefore, are more likely to respond according to the
later considered standard hypothesis that the protagonist will appear at B. As a
consequence, they would look and move the mat more often to A than they verbally
respond with A because their looking and mat moving tend to be quick, while their
verbal responses tend to be slower and more deliberate.
To test this possibility that children entertain two quite explicit theories that differ in
their temporal processing characteristics , we monitor children’s timing of their
responses in all three conditions. If the results show that responding with location A in
the false belief story depends primarily on quicknes s of response and not whether it is a
mat-moving or a verbal response (mat moving just tends to be quicker than answers to
questions), then the temporal stacking hypothesis can save the explicit-knowledge-onl y
hypothesis. If, however, there is a difference between mat-moving and verbal responses
independentl y of any effect of response timing, then the temporal stacking hypothesis
can be rejected as a complete explanation of the data.
In contrast, the findings from the use of implicit knowledge (Rossetti, 1998) in the
context of illusions (Bridgeman et al., 1981), information presented close to threshold,
and information presented to the blind field of blindsight patients (Marcel, 1993)
suggest that the use of implicit knowledge is available only to spontaneous action but
not to delayed action. Hence, the implicit-knowledg e hypothesis would let us expect
that spontaneous mat moving should yield more correct A responses than delayed,
prompted responding. Without the advantage of implicit knowledge, prompted
responding should yield about the same level of A responses as answers to questions
(anticipate-protagonist , reflect-mat-move). No timing effect would be expected for
answers to questions. Since all visual orienting responses (in the time window measured)
are spontaneous responses, the level of A responses in looking should be the same as for
spontaneous mat moving.
Method
Participants
Seventy-four children aged 2;5 to 4;3 from five playgroups in predominantly middle-class areas of
False belief in action
423
Brighton, Hove and Portslade took part in this study. One child did not have English as his/her first
language but gave correct responses on all measures. Three children had to be excluded from the analysis.
For two of them (aged 2;6 in anticipate-protagonis t condition and 3;7 in reflect-mat-mov e condition), a
dark shadow present on the videotape recording prevented monitoring of children’s response timing.
One other child (aged 2;11 in reflect-mat-mov e condition) refused to sit long enough to complete the
first task. This left the data from 71 children (38 boys and 33 girls) with a mean age of 3;3 for further
analysis: 24 in the anticipate-protagonist , 23 in the mat-moving and 24 in the reflect-mat-mov e
conditions.
Materials
Two scenarios were used in this experiment. In addition to the playground scenario (as used in
Experiment 1), a large fire station scenario was used. The fire station was a large 50 cm (length) 6 30 cm
(height) 6 25 cm (width) three-dimensiona l model made of card depicting the following scenario. A 26
cm (height) 6 10 cm (width) flight of steps separated two areas of the fire station. At the foot of the steps
in the mat-moving and planned-actio n conditions, a small 10 cm 6 8 cm brown mat (as used in the
previous experiment) was placed. The steps led to a doorway that, as the child learnt during the
familiarizatio n phase, was the entrance to the firemen’s tea-room and also the entrance to the top of the
slippery poles. Each slippery pole was situated in one of two fire station areas. The poles were constructed
using the blunt ends of two large, thick knitting needles that had been painted. One pole was painted
navy blue, and one pole was painted bright green. Each pole protruded from a small circular opening (that
remained invisible to children unless they actively looked under and up to the top of the fire station).
A small box, 4 cm 6 4 cm, was positioned approximately 3 cm in front and 2 cm to the side of each
pole. The boxes were painted in exactly the same colours as the poles that they were positioned next to.
The object to be transferred in this scenario was either a small bucket or a fire extinguisher taken from
the playmobile fireman set. Two playmobile figures, one male and one female, were used as the
characters.
Design
In order to avoid information overload in children and the danger of carry-over effects, a betweenparticipant design was used with each child being randomly assigned to one of three conditions:
anticipate-protagonist , mat-moving and reflect-mat-move . Each child was tested in a single session and
heard one false belief and one true belief story presented in counterbalanced order and with
counterbalanced assignment of story scenarios (playground vs. firemen). Visual-orienting responses were
only monitored in the anticipate-protagonis t condition because of the presence of the mat acting as a
distractor in the other two conditions. To avoid the possibility that children in the mat-moving
condition were given unfair advantage by practising the required response in the familiarizatio n trial,
such a trial was administered in all three conditions. This trial differed from test trials in that there was
no transfer of the object from one location to the other.
Procedure
The same procedure as in Experiment 1 was employed with the exception that in the reflect-mat-mov e
condition, different instructions were given to the child. Children were asked where they were going to
move the mat before they had actually executed the action of moving it. In all conditions, the
experimenter kept the characters out of sight behind the story model until a response had been given.
This methodological precaution was to avoid any possibility that children might use the shape or size of
the experimenter’s hands (one of which contained the protagonist figure) as a clue to where the
protagonist was going to come down.
Scoring of responses. The scoring of responses was done as in Experiment 1. Inter-rater agreement was again
a high 97% (184 of 190, k = .96) for all responses taken together. For visual responses alone, inter-rater
agreement was 89% (43 of 48, k = .83). Each response was also coded according to the time taken to
424
Wendy A. Garnham and Josef Perner
give a response: given without hesitatio n within a second (a spontaneous response), oscillated between
the two locations before deciding on the answer (an oscillating response) or needed further prompting
before giving a correct answer leading to a delay of several seconds (a prompted response). As there were
only six children in the mat-moving condition who ever oscillated between the two locations before
giving a response, and since oscillatin g responses and prompted responses were given only after
hesitation, these responses were grouped together for the purposes of further analysis.
Results and discussion
We start by analysing the data in the same way as in Experiment 1 to validate children’s
AB responses (respond with A in the false belief and with B in the knowledge control
story) as indicators of understandin g belief-based action. Since the incidence of B
responses in the true belief condition is very high, we simplify the analysis by looking
exclusively at children’s responses in the false belief story.
Validation of AB responses
Table 2 confirms the finding of Experiment 1 that the incidence of the AB response
pattern does reflect understandin g of belief because it is quite frequent in contrast to the
BA pattern as our best estimate of purely random responding. In fact, the BA pattern is
extremely rare and is shown only by children below the age of 3 years. For each
condition except the answers to the predict-protagonis t question, binomial tests show
the difference between AB and BA to be highly significan t (all ps < .01).
This means that the AB pattern is (except for the answers to the anticipateprotagonist question) a fairly accurate indicator of understandin g that the protagonist
will reappear at location A in the false belief story. Moreover, the lower panel of Table 2
also shows that the incidence of A responses in the false belief story deviates minimally
from the incidence of the AB pattern, in particular, for the looking and mat-moving
behaviour. This implies that we can also rely on the incidence of A responses in the false
belief story as a fairly safe indicator of understandin g belief-base d action. This
consideratio n is important for practical reasons: it allows us to restrict the ensuing
analysis of the timing and condition factors to the data from the false belief story. This
analysis would otherwise become quite complicated.
Effect of timing and condition on A responses in the false belief story
The scoring of children’s response timing in the false belief story showed a fairly even
spread of spontaneous responders and children who needed prompting: 15 spontaneous
and nine prompted in the anticipate-protagonis t condition, 11 and 12 in the matmoving condition, and 12 and 12 in the reflect-mat-move condition.
In order to investigate the effect of the timing factor on children’s responses in the
different conditions, we carried out a logistic regression using the BMDP (LR) statistical
software package (Dixon, 1992) specifying the following model: timing 6 condition
with the proportion of A responses as dependent variable. Factor timing has two levels
(spontaneous vs. prompted) and condition three levels (anticipate-protagonist , mat
moving and reflect-mat-move). The pairs of bars in Fig. 1 show the relevant data for this
analysis. They show for each condition the percentages of correct A responses separately
for spontaneous responders and for children that needed prompting.
False belief in action
425
Table 2. Number of children showing particular response pattern across the two stories
and the relative frequency of A:B responses for each story individually in Expt 2
Condition and response mode
Response pattern or story
Anticipate-protagonis t
Looking
Answer
Response pattern over false and true belief story
AB
15
5
BA
1
3
AN and NB
1
0
NA and BN
0
0
AA
1
2
BB
4
14
NN
2
0
Frequency of A:B responses
False belief story
16:5
7:17
True belief story
2:20
5:19
a
Move mata Reflect mat move
11
0
0
0
1
11
0
6
0
0
0
2
16
0
12:11
1:22
8:16
2:22
Only 23 children in this condition
The two main effects of timing (w2 (1,71) = 8.19, p < .004) and condition
(w (1,71) = 7.87, p < .02) were both highly significant , but their interaction failed
to be so (w2 (2,71) = 5.11, p > .08). There is a slight danger that these two effects are
not independent , because timing was not an experimentall y manipulated but an
observed variable. To check on this possibility, condition is introduced first into a
stepwise regression. Timing still remains as a significant independen t predictor
(w2 (1,71) = 12.19, p < .001). Similarly, when timing is introduced into the stepwise
regression, condition stays highly significan t (w2 (1,71) = 12.05, p < .002). This is
important because it makes clear that response timing does not explain the effect of
condition.
The main effect of condition can be seen most easily in the lower panel of Table 2
showing that in the false belief story, 12 of 23 (52.2%) children moved the mat to A,
while only seven of 24 (29.2%) in the anticipate-protagonis t and eight of 24 (33.3%) in
the reflect-mat-move condition answered with A. This effect is also reflected in Fig. 1 by
the fact that each of the two bars in the mat-moving condition is higher than its
corresponding bar in the two other conditions (answers to anticipate protagonist
question and to reflect-mat-move question).
The effect of timing can be seen in Fig. 1 from the fact that spontaneous responders
showed more A responses than children who needed prompting in each of the three
conditions. That this difference seems to be larger for mat moving than for answers to
the anticipate-protagonis t question and larger than for answers to the reflect-mat-move
question reflects the non-significan t but still noticeable interaction between timing and
condition.
2
426
Wendy A. Garnham and Josef Perner
Figure 1. Comparison of spontaneous and prompted responses in each condition.
False belief in action
427
The left-most bar in Fig. 1 shows the incidence of looking to A in the anticipateprotagonist condition for comparison. We now use the complete pattern of results
displayed in Fig. 1 to test for direction-specifi c comparisons that were predicted a priori
by one of our three hypotheses under consideration using one-tailed tests of significance .
Implicit knowledge hypothesis
As mentioned in the introduction to this experiment, the results from studies of adults’
visually guided action and visual perception in the context of visual illusions indicate
that implicit knowledge tends to be available only for spontaneous, and not for delayed,
actions (see review by Rossetti, 1998, which also covers parallel effects in neurological
patients). On these grounds, the implicit-knowledg e hypothesis predicts that precocious
implicit knowledge should be mainly available for spontaneous, but not for prompted,
hesitant mat-moving actions. This is indeed the case as shown in Fig. 1
(w2 (1,23) = 3.56, p < .05, one-tailed). The hypothesis does not predict a similar
timing difference for answers to questions; the data in Fig. 1, however, suggest that
there might be. This difference speaks for the temporal stacking hypothesis and cannot
be accounted for by the implicit-knowledg e hypothesis.
The implicit-knowledg e hypothesis also predicts that precocious implicit knowledge
should be available only for spontaneous action, not for spontaneous answers to
questions. This prediction, too, is reflected in the data as the mat is moved
spontaneously more often to A than there are spontaneous answers to questions
(anticipate-protagonis t and reflect-mat-move question combined: w2 (1,38) = 3.37,
p < .05, one-tailed). Also reassuring for the implicit-knowledg e hypothesis is the fact
that the relative incidence of looking to A in the anticipate-protagonis t condition, i.e.
spontaneous eye movements for the whole sample (left most column in Fig. 1), does not
exceed and closely matches the incidence of spontaneously moving the mat to A.
Misinterpretatio n hypothesis
Our critical test of the misinterpretation hypothesis was children’s answers to the
reflect-mat-move question. The hypothesis predicts that children (1) perform better on
this than on the anticipate-protagonis t question and (2) give as many A answers to this
question as children look to A, or (3) move the mat to A. This is so because the
misinterpretatio n depressing performance on the anticipate-protagonis t question does
not apply to the reflect-mat-move question.
Clearly, Fig. 1 or the A:B ratios in the penultimat e row of Table 2 show little
evidence for prediction (1) of superior performance on the reflect-mat-move question
over the anticipate-protagonis t question (w2 (1,48) = .10, p > .50, one-tailed). The
available evidence actually speaks against prediction (2) that the reflect-mat-move
question should be answered as often with A as children look to A. As Fig. 1 and Table
2 show, there is a substantial difference (w2 (1,48) = 5.33, p < .05, two-tailed).
Moreover, there also seems to be a difference between mat moving and the reflect-matmove question that speaks against prediction (3), but this difference is not statistically
reliable (w2 (1,48) = 1.70, p > .10, two-tailed).
428
Wendy A. Garnham and Josef Perner
Temporal stacking hypothesis
The significan t factor of timing in the logistic regression provides positive evidence for
this hypothesis. However, what differentiate s it from the implicit-knowledg e hypothesis
is the timing effect in the explicit question conditions (anticipate-protagonis t and
reflect-mat-move questions). Although the difference between spontaneous and
prompted answers in these conditions is not as marked as for mat moving, it is almost
significan t (w2 (1,48) = 2.59, p < .06, one-tailed). This difference cannot be explained
by any of the other hypotheses and speaks, therefore, specificall y for the temporal
stacking hypothesis.
However, the data also make clear that the difference between looking to A and
answering the anticipate-protagonis t question with A cannot be accounted for fully by a
difference in timing. The incidence of visual orienting responses to A (see Fig. 1) is
higher than the spontaneous A responses in the two explicit question conditions—a
difference predicted by the implicit-knowledg e hypothesis but not by temporal stacking
(w2 (1,52) = 3.38, p < .05, one-tailed). Similarly, children move the mat spontaneously
more often to A than they spontaneously answer the direct questions with A
(w2 (1,38) = 3.37, p < .05, one-tailed). The fact that this aspect of the data cannot be
accounted for by temporal stacking is also underlined by the significan t factor of
condition after partialling out timing in the logistic regression analysis.
Summary evaluation
The implicit-knowledge hypothesis provides a reasonably good fit to the data. It can
account for the difference between spontaneous and prompted (delayed) mat-moving
responses and for the fact that moving the mat spontaneously is superior to answering
direct questions—be it spontaneous or prompted. It cannot account for the timing
difference in the direct question conditions. The temporal stacking hypothesis can account
for the timing differences in all three conditions, but cannot account for the effect of
condition independentl y of any timing differences . The misinterpretation hypothesis
received no clear support, which does not mean that other forms of misinterpretation are
not possible that might be compatible with the pattern of data obtained.
GENERAL DISCUSSION
The presented data provide support for the hypothesis that precocious understandin g of
belief-based action expressed in children’s anticipatory eye movements (Clements &
Perner, 1994) is implicit knowledge possibly lacking conscious awareness. The support
for this hypothesis is twofold. First, the usability of precocious knowledge depends on
the same factors as the use of implicit knowledge in adults. Secondly, the implicit
knowledge hypothesis provides a better fit to the data than several performance
hypotheses designed to support the explicit-knowledge-onl y hypothesis.
The first kind of support for the implicit-knowledg e hypothesis is based on findings
from adults’ implicit knowledge gained from processing visual information without
conscious awareness (see Rossetti, 1998 for a review) in healthy participants perceiving
visual illusions and in blindsight patients. Two factors are critical for participants ’
ability to use such implicit knowledge. The knowledge can be used for acting or
False belief in action
429
orienting oneself in the world but not for answering a direct question about the state of
the world, and any action must be carried out without delay. Both these factors seem
necessary conditions for children’s use of their precocious understandin g of where a
mistaken protagonist will go to find an object. Their precocious knowledge shows in
their visual orienting to the world and in their spontaneous actions (mat moving) but
not in their answers to direct questions (anticipate-protagonis t and reflect-mat-move
question). Furthermore, children can use this knowledge only when acting
spontaneously but not after hesitation and a prompt by the experimenter . The
hypothesis leaves unexplaine d why there is also some advantage to answering direct
questions spontaneously.
The second kind of support for the implicit-knowledg e hypothesis comes from the
fact that none of the alternative performance hypotheses (designed to save the explicitknowledge-onl y hypothesis) can account for the effectivenes s of both these factors. The
lack-of-confidence hypothesis fails to explain why spontaneous mat moving leads to more
A responses than spontaneous answers to direct questions. The temporal-stacking
hypothesis can explain why there are timing difference s for action and for answers to
direct questions, but fails to account for the fact that visual orienting responses and
spontaneous mat moving yield more A responses than spontaneous answers to direct
questions. Finally, the misinterpretation hypothesis cannot account for the fact that the A
responses to the reflect-mat-move question were not higher than to the anticipateprotagonist question, and why they stayed less frequent than looking to A and
spontaneously moving the mat to A.
It should be pointed out that this negative evidence pertains, of course, only to the
precise versions of these hypotheses considered at the beginning . It may not extend to
new versions of, for example, the misinterpretation s hypothesis. As one anonymous
reviewer pointed out, the anticipate-protagonis t question and the reflect-mat-move
question are very similar with respect to using the continuous future, which presents a
difficult y for children at this age. Some children therefore may be equally confused in
both conditions and answer with location B in the false belief story because they take the
point of the game to be moving objects from A to B. This would save the explicitknowledge-onl y hypothesis, because they could have explicit knowledge that shows in
their visual orienting response and in spontaneous mat moving but becomes masked
through their incomprehensio n of the future tense in the direct questions. Future
research needs to investigate the possibility of such a misinterpretation. However, even
this version of the misinterpretatio n hypothesis would not account for why children
move the mat more often to A when acting spontaneously than when prompted to act.
Apart from these performance hypotheses that we have considered from the outset,
other suggestions have arisen of how to save the explicit-knowledge-onl y hypothesis.
Zelazo, Frye, and Rapus (1996) suggested that the visual-orienting responses in the
study by Clements and Perner (1994) are not implicit but rather abulic in analogy to the
dissociation reported by these authors: children who can state explicitly the rule by
which they should sort cards but, when given a card, sort it wrongly according to an old
or predominant rule. The dissociation observed in the present research, however, is of a
different nature. There is no evidence that children can state the correct rule (protagonist
goes to A) and then fail to act accordingly (e.g. move mat to B). In fact, the evidence
points in the opposite direction.
430
Wendy A. Garnham and Josef Perner
Another possibility of avoiding any recourse to an implicit knowledge base is to
suggest that the looking to A or moving the mat to A is not based on any knowledge.
Rather, it is owing to an association created by the protagonist putting the object
originally into that location. This association is also created in the true belief control
story, but because the protagonist is also present when the object is moved to B, an
association to B is formed as well, weakening the response tendency to look (move mat)
to A in that condition. With the further assumption that associations operate faster than
inferential reasoning (i.e. they are temporally stacked), this hypothesis can explain why
spontaneous mat moving tends to be more likely to be directed at A than prompted
moving. Despite its predictive potential, this hypothesis remains very implausible for
several reasons. The competing association with B in the knowledge condition could at
best reduce the response tendency towards A observed in the false belief condition and
not reduce it to practically zero as is the case in all age groups (except for the group of
children younger than 3 years). Moreover, this hypothesis also leaves unexplained why
there are fewer spontaneous A answers to the anticipate-protagonis t question than
spontaneous mat moves or visual-orientin g responses to A.
A final attempt to explain the findings in terms of a single, exclusively explicit
knowledge base follows the theory of graded representations by Munakata, McClelland,
Johnson, and Siegler (1997). This theory is to explain why young infants in object
permanence tasks show the A-not-B error more often in their manual search (looking
erroneously for the object in location A where it had been hidden on previous trials
instead of looking in the current location B) than in their looking behaviour (Diamond,
1988; Hofstadter & Reznick, 1996). The theory of graded representation is based on the
workings of a connectionis t network and the assumption that an activation level of
about 20% of the final asymptotic level suffices for governing eye movements, but that a
level of 80% is required for manual search. This explanatio n has a certain similarity to
our lack-of-confidenc e hypothesis (i.e. weak, unreliable activation governs exploratory
eye movements but not action). Our findings, however, showed that mat moving is
governed to practically the same degree by this weaker representation than eye
movements. Moreover, the theory also fails to explain why spontaneous mat moving is
more likely to be governed by this allegedly weaker but otherwise similar representatio n
and why it is not used for answers to questions.
In conclusion, the main finding in this study is that a precociously correct
understandin g of where a mistaken character will look for an object is only revealed in
(1) either visual-orientin g responses or actions but not declarative expressions of what is
going to happen, and (2) in action only when these actions (mat-moving responses) are
spontaneous but not when prompted. These two features find a clear parallel when
implicit (unconscious and unable to be verbalized) knowledge dissociates from explicit
knowledge under illusory perceptual conditions or neurological conditions (blindsight )
leading to a loss of conscious awareness. Hence, this pattern of results fits best the
hypothesis that children’s precocious knowledge is based on an implicit understandin g
without conscious awareness. Several performance hypotheses designed to show that this
precocious knowledge could be based on explicit knowledge met with less success. Some
more refined versions of these hypotheses (e.g. refinement of the misinterpretatio n
hypothesis) require further research.
False belief in action
431
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Appendix
Verbatim example of the false belief story of the football scenario
Episode 1
This is Alan. If Alan wants something from this red box, he comes down the red slide. If he wants
something from the blue box, he comes down the blue slide. Alan put his football in the red box. [Order
of where he put the football was counterbalanced.] Then he climbed all the way up the steps and walked to
the top of the slide. [Alan cannot be seen by the child once he has entered the door at the top of the steps.]
Episode 2
All of a sudden, in came Rebecca. She wanted to play with the football. She took the football out of the
red box and played with it. ‘I’ll go and get a drink now’, she said. She picked up the football and put it
into the blue box in the other playground area. Then she went to get a drink.
[Rebecca is moved behind the model out of sight. Two prompt questions are then asked to ensure that
the children have attended to the critical story events.]
Prompt question 1: Where did Alan put the football right at the beginning?
Prompt question 2: Did Alan watch Rebecca move the football?
[If any of these questions was answered incorrectly, the story was repeated from the beginning.]
Episode 3
‘I’ll go and get my football now,’ said Alan.
[It was at this point on the video clip that the two independent raters were asked to determine where the
child was looking preferentially . After the critical 2–3 s time period, the experiment proceeded with the
experimenter asking the child either to move the mat to catch the protagonist (mat-moving condition) or
give a verbal prediction of where the protagonist would look for the desired object (behavioural
prediction condition). In both cases, the experimenter moved both clasped hands to the top of each slide.]
Anticipated-action question (anticipated-actio n condition): Where is Alan going to look? Mat-moving
instructions (mat-movin g condition): Quick! Move the mat to catch Alan as he comes down the slide!
[Three memory questions were then asked to ensure that any failure to give a correct verbal or matmoving response was not owing to an inability to remember the critical story events.]
Memory question 1: Where did Alan put the football right at the beginning?
Memory question 2: Where is the football now?
Memory question 3: Did Alan see Rebecca move the football?