1
The
British
Psychological
Society
British Journal of Developmental Psychology (2012), 30, 1–13
C 2012 The British Psychological Society
www.wileyonlinelibrary.com
Editorial
Implicit and explicit theory of mind: State
of the art
Jason Low1, ∗ and Josef Perner2
1
2
Victoria University of Wellington, New Zealand
University of Salzburg, Austria
From their different vantage points, the contributors to this issue address the developmental puzzle of infants as young as 14 or 15 months (Onishi & Baillargeon, 2005; Surian,
Caldi, & Sperber, 2007) displaying sensitivity to people’s mistaken false-belief-based
behaviour in certain tasks, when it has proved difficult to show any such understanding
before 3 or 4 years (Wellman, Cross, & Watson, 2001) in many variations of the traditional
false-belief test (Wimmer & Perner, 1983). Borrowing from the consciousness literature,
these classes of tasks can be called indirect and direct tests. In the traditional falsebelief test and its variations, children are directly asked about the mistaken agent’s
belief or behaviour, while in the tasks used with young infants any understanding
has to be inferred indirectly from infants’ or toddlers’ spontaneous behaviour in the
test situation. Baillargeon, Scott, and He (2010) used the cognate characterization of
induced as opposed to spontaneous responding. Understanding shown in an indirect
test when no such understanding is shown on the direct test is one of the hallmarks
of implicit or unconscious knowledge (Merikle & Reingold, 1991). On these grounds,
Perner and Clements (2000) spoke of implicit understanding of belief. The implicit–
explicit distinction has however become a general expression of marking the intuitive
difference between an inchoate earlier and a more robust later understanding.
The Nature of Development: Negative Release or Positive Gain
One can caricature two basic positions of what underlies the observed cognitive changes.
One view assumes that knowledge of basic principles (core theory) is present early on
but infants and young children cannot make full use of it because of constraints external
to the content of their knowledge. These constraints may be limited memory capacity
or insufficient inhibition of interfering processes. Only when children are released from
∗
Correspondence should be addressed to Jason Low, School of Psychology, Victoria University of Wellington, PO Box 600,
Wellington 6140, New Zealand (e-mail: Jason.Low@vuw.ac.nz)
DOI:10.1111/j.2044-835X.2011.02074.x
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Jason Low and Josef Perner
these negative constraints can they use their knowledge in increasingly complicated
tasks. The contrasting view is that development consists in a positive gain of new
principles being discovered or maturing. As a specific case of this dichotomy, San Juan
and Astington (pp. 105–122, 2012) mention nativist modular accounts in distinction to
constructivist conceptual shift accounts.
As an example of negative release, Baillargeon et al. (2010) contend that standard
direct false-belief tasks tap not only the false-belief representation system but also
children’s skills in inhibiting their own perspective and selecting a response to the
direct test question. This account posits that only the psychological reasoning system
is engaged in indirect false-belief tasks where expectant or anticipatory looking is
measured. This cannot explain why Clements and Perner (1994) found no evidence
of correct anticipatory looking in children younger than 2 years 11 months. He, Bolz,
and Baillargeon (pp. 14–29, 2012) raised the possibility that this may have been due to
the use of a ’I wonder where he will come out?’ prompt, which children below age 3 may
have understood as a direct question, which turned the task into a direct task. To help
children, the authors added a spontaneous false-belief condition where the experimenter
delivered the anticipatory prompt as a self-directed utterance (stared at ceiling with chin
in hand) and compared it to a question condition where the experimenter looked directly
at the child when uttering the prompt. Two-and-a-half-year-old children looked longer
at the original (belief relevant) location in the self-addressed experimenter utterance
condition than in the question condition.1
The approach complements German and Cohen’s (pp. 45–58, 2012) emphasis on cue
encoding, which advocates characterizing the matrix of contextual input information
(e.g., self-directed utterance vs. direct question) that engages the theory of mind (ToM)
network. Also, the finding by Surian and Geraci (pp. 30–44, 2012) supports an early
competence view. Seventeen-month-olds showed correct anticipatory looking in a
false-belief situation even when the ’agents’ are morphologically very different from
familiar or natural agents. They contend that evidence of early attribution of beliefs to
geometric shapes weakens the possibility that domain general associative mechanisms,
fed by learning experiences involving familiar human agents, play a crucial role in the
development of children’s psychological reasoning system.
A different explanation assumes positive gain. The performance lag on the two
sets of false-belief evidence – spontaneous looking in indirect tasks and elicited
verbal2 prediction in direct tasks – suggests the operation of two distinct systems of
understanding: an early-developing implicit system that is piecemeal and unconscious
and a later-developing explicit system that is abstract and conscious (Low, 2010).
Proponents of the positive gain view differ in terms of how they flesh out the meaning of
’implicit’. Rakoczy (pp. 59–74, 2012) cautions that it may be of limited explanatory help
to call some precocious abilities in infants ‘implicit ToM’ without further qualification.
1 This
result is undoubtedly interesting but the tasks are not ’anticipatory looking’ tasks as used by Clements and Perner
(1994), where the agent (or the agent’s hand, Southgate, Senju, & Csibra, 2007) reappears at different locations so that the
child’s looking anticipates where the agent will reappear. While in this study children’s longer looking at the object’s original
location is not an obvious indicator of any action by the agent. In fact, Garnham and Perner (2001) separated the location of
the object from the agent’s point of reappearance and found only looking at the point of reappearance and not to the object’s
former or present location.
2 Data by Garnham and Perner (2001) suggest that non-verbal behaviour such as moving a mat to the point of the agent’s
return pose the same problem unless it occurs spontaneously without much reflection in analogy to action based on implicit
knowledge in the consciousness literature (Perner & Clements, 2000).
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Rakoczy alerts us to the fact that we lack data to establish whether infants’ apparent
sensitivity to false-belief inducing situations warrants ascription of beliefs about beliefs.
Infants’ sensitivity may not be inferentially sufficiently integrated to warrant either the
inference that what they are sensitive to are beliefs of the agent, or that their sensitivity
is a belief or some ‘subdoxastic’ state (Stich, 1978). It is particularly difficult to pinpoint
whether infants operate with a full-blown unconscious concept of belief or with simpler
psychological states that play a role in the causal history of beliefs but are not beliefs
themselves.
Apperly and Butterfill (2009) favour the view that there may be an efficient earlydeveloping implicit system that tracks intermediate ’belief-like’ states (sensitivity to
another’s engagement to or registration of an object or event), and such understanding
may be revealed in spontaneous or indirect measures. This view is promising insofar
as one is able to pinpoint real limits on the kinds of input that the implicit system will
process. Qureshi, Apperly, and Samson (2010) tested Level-1 perspective taking whereby
adults had to judge how many dots an avatar could see. In the critical self-trials (which
serve as an indirect measure of taking the other person’s perspective), adults were slower
and more error prone in judging their own perspective when the avatar had a different
perspective of the number of dots than when his perspective was the same as theirs. This
interference suggested that adults were efficiently processing the avatar’s perspective
even though it was not required for their own explicit predictions (which make it
an indirect assessment of other’s perspective). On the basis of such findings, Surtees,
Apperly, and Butterfill (pp. 75–86, 2012) tested Level-2 perspective taking by inviting
6- to 11-year-olds and adults to make judgments about the appearance of numerals that
appeared different depending on viewing position (e.g., 6 and 9 painted on the floor
between themselves and the avatar). No interference was found on the self-trials when
the avatar’s perspective of the numerals was different from the participants’. There was
only evidence of interference of participants’ own perspective on the direct measure
of Level-2 perspective taking. Thus, Surtees et al. view the Level-1/Level-2 distinction
as one signature limit on implicit, automatic perspective taking. However, in reviewing
the automaticity literature, German and Cohen (2012) alert readers to other evidence
pointing to a neural signature of ToM that occurs even when there is no value or need
to track others’ belief for task performance.
A new paradigm developed by Kovács, Téglás, and Endress (2010) is also attracting
debate amongst contributors as to whether there is genuine conceptual gain in belief
understanding. In Kovács et al.’s task, 7-month-olds viewed the following scenes with
a Smurf agent observing a ball move behind a barrier. In a false-belief condition, the
Smurf left, and the infants witnessed the ball moving from behind the barrier and leaving
the scene. Thus, the Smurf falsely believed there was a ball behind the barrier. The
Smurf returned and the barrier was lowered to reveal (to the Smurf’s but not the infant’s
surprise) the ball. In the true-belief condition, the Smurf also saw the ball leaving the
scene, and hence shared this knowledge with the infant. Infants looked longer at the
ball behind the lowered screen in the false-belief condition when this was surprising for
the Smurf than in the true-belief condition. The authors argued that this showed that
infants computed the Smurf’s belief online. Parallel results were obtained with reaction
times in adults. There, the effects did not hold when the Smurf was replaced by a pile
of boxes. These findings epitomizes the cue-encoding approach for German and Cohen
(2012), where the presence of an agent is one critical cue to meeting input conditions
for triggering ToM computations.
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Jason Low and Josef Perner
Surian and Geraci (2012) see the results by Kovács et al. (2010) also as a successful
extension of the earlier findings by Onishi and Baillargeon (2005) and Surian et al.
(2007) on older infants to a much younger age. However, Ruffman, Taumoepeau, and
Perkins (pp. 87–104, 2012) point out that in this task, the infant’s looking does not
constitute a prediction of, or a response to, a character’s search behaviour. The effect
on looking time may, therefore, not be caused by representing a belief that governs
the Smurf’s behaviour, but by registering the Smurf’s differing perceptual access (which
would be needed for computing his beliefs about the ball). In other words, infants may
be very sensitive to registering what happened in the presence and what happened in
the absence of an agent. The representation that the ball was still behind the screen
when the Smurf was present could be the cause of infants longer looking as much as
representing the Smurf’s belief about the ball’s location (Perner, in press-a).
Ruffman et al (2012). are also less sanguine about rich interpretations of data from
a range of tasks meant to tap infants’ understanding of goals and intentions. They argue
that infants use experiences of behaviour sequences (supported by statistical learning
skills) rather than mental states to reason about outcomes. Short of children offering
verbal explanations with overt mental-state terms when justifying their predictions
(‘because that’s where Maxi put the chocolate’ vs. ‘because he thinks it is still there’
– the latter is rare even after 6 years of age) looking responses may indicate a shallow
causal understanding of how people act in certain situations (based on smart encoding,
Perner, 2010, or behaviour rules, Povinelli & Vonk, 2004) rather than a deep analysis
in terms of intervening mental states. Thus, children’s looking responses may be based
on situation-action rules that provide an implicit sensitivity to actions (mentally caused
behaviour) without explicitly representing the mental intermediates in the causal chain
from situation to action.
Their explicit understanding of how people act and why may be grounded in
teleology, that is, action that objectively achieves a worthy goal. This is a plausible
explanation for why children give systematically wrong answers in the standard falsebelief test, for Mistaken Maxi has good objective reasons to go where his chocolate
actually is. The developmental consequence is that children become able to understand
false-belief tasks at around 4-years when they understand different perspectives (Perner,
Mauer, & Hildenbrand, 2011) and that agents do not act according to objective reasons
but according to their subjective reasons that present themselves as objective reasons
within the agent’s subjective perspective (Perner & Roessler, 2010).
Behaviour and Mental-State Rules
Mental-state rules are computational behaviour–mind–behaviour rules, which a mentalist
(mind reader) needs to infer from an agent’s observable situation and behaviour the
agent’s mental states – beliefs and desires – and from these states what the agent is likely
to do. The rules by which we predict and explain behaviour (mind to behaviour) are – so
is commonly thought – accessible to us and they can be formulated as practical syllogism
(Aristotle, see Kraut, 2009; Gopnik & Meltzoff, 1997): ‘people take those (instrumental)
actions of which they think they will achieve what they want (their goal).’ The rules that
lead from observed behaviour to mental states, on the other hand, tend to be opaque to
us but must exist in our sub-personal cognitive mechanism in order for our ToM to work.
Behaviour rules (Povinelli & Vonk, 2004) are of this sub-personal kind. Instead of leading
from behaviour to mental states they lead directly to predicted behaviour. Povinelli and
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5
Vonk argued that any mentalist explanation of making correct behavioural predictions
can easily be changed to a behavioural rule explanation by simply taking the mental
step out of the explanation and substituting it with a direct predictive link to the future
behaviour. In other words, a behaviour rule explanation can account for the same set
of behavioural predictions as a ToM approach. The two are computationally equivalent
and they therefore cannot be distinguished by investigating what kind of predictions
one can make but only by using cognitive measures that tap how these predictions are
made (e.g., Perner, 2010; see also Ruffman et al., 2012).
With this background in mind, the reader can critically evaluate the proposal by He
et al. (2012) who analyse the mental state approach as involving but one general rule:
agents who are pursuing a goal will act on information available to them. He et al. admit
that, by other measures, mental rules will be more complex by involving an additional
step than situation-action behaviour rules, but they maintain that, overall, ‘far fewer
[mentalistic] rules will be needed across situations’ because mentalistic rules are general
and apply to a variety of situations. Surian and Geraci (2012) concur and argue that a
behaviour rule account would have to concoct more and more situation-action rules
that would explain the looking times found in different studies. That this should be so
is not immediately apparent, since for existing studies every behaviour-mental rule can
be turned into corresponding behaviour-behaviour rule (Povinelli & Vonk, 2004). In any
case, even if an unruly concoction of behaviour rules is needed to predict behaviour,
why would this count against behaviour rules? Evolution, we are told, does not select
for elegant systems but for fast and dirty rules (Gigerenzer, 2004).
San Juan and Astington (pp. 105–122, 2012) caution that it is not even clear that
children of a given age apply their implicit knowledge or understanding across situations.
Although behaviour rules can apply to verbal predictions as well, there is wide (perhaps
premature) agreement that from around age 4, children (in different cultures as well)
pass different false-belief tasks at the same time (e.g., unexpected transfer, unexpected
contents, misinformation, appearance reality), and are able to deploy their attributions
for different uses or demands (e.g., judging where agents will look for, where they will
think, what they will say, where they will point to; see Wellman et al., 2001). It is
this flexible combination of different belief-inducing situations and different purposes
that is most telling of a ToM over behaviour rules (Perner, 2010). Studies examining
infants have used a variety of belief-inducing situations but only a very limited number
of purposes, for example, where someone will go or reach. Moreover, infant studies
with looking duration are rarely conducted using a within-subjects design, qualifying the
claim that early understanding generalizes across situations even further (Low & Wang,
2011; Rakoczy, 2012; San Juan & Astington, 2012).
Whilst there is some diversity in false-belief formation scenarios tested across
violation-of-expectation studies, anticipatory looking data are based only on the
unexpected-transfer scenario (Low & Wang, 2011). Wang, Low, Jing, and Qinghua
(pp. 123–140, 2012) used a within-subjects design to test whether Mainland Chinese
preschool children would also show dissociation between anticipatory looking and
verbal predictions across different belief-inducing contexts at the same time: unexpected
transfer, unexpected contents, and misinformation. Individual Chinese 3- and 4-year olds
showed accurate anticipatory looking across the false-belief task contexts despite erring
on their explicit verbal predictions. Individual children’s anticipations cohering across
diverse false-belief scenarios would fit with He et al.’s (2012) analysis that only one
general rule is required under the mental state approach – but only at a high level of
analysis. The cognitive apparatus must also solve the lower level analysis getting from
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observables to mental states. Thus, based on Perner’s (2010) analysis of mental state
and behaviour rules, behaviour rules would also (and better) explain Wang et al.’s
data showing children’s accurate anticipations across scenarios. Depending on how one
analyses or counts rules, advocates of either a rich or lean interpretation can claim to
have parsimony’s support on their side (for whatever that is worth).
Vierkant (pp. 141–155, 2012) argues that infants compute false belief and the
representation guides aware intentional action – best showcased in active helping and
referential communication studies by Buttelmann, Carpenter, and Tomasello (2009)
and Southgate, Chevallier, and Csibra (2010), respectively. He suggests that verbal
reporting – as is often the case in traditional false-belief tasks – may be misleading
as the gold standard for ascribing mental-state awareness. Even those studies are open
to behavioural interpretations. Consider Buttelmann et al.’s false-belief condition. An
agent fails to witness her favourite toy being moved and returns to the first box to
retrieve it but could not get to open the box. Children were then asked to ’help’ the
agent: over 70% of 18-month-olds approached the second box. In contrast, less than
20% did so in a knowledge condition where the unsuccessful agent had witnessed the
transfer to the new box but tried to open the empty box. Buttelmann et al. suggested
that toddlers approached the second box in the false-belief condition because they
recognized that the agent falsely believed that her toy was still inside the first box and
concluded from the agent’s unsuccessful attempt to open that box that she wanted to
retrieve the toy she thought was in that box but that was now in the new box. So, the
child had to orient to the new box to retrieve the desired toy. Instead of concluding
that toddlers have a concept of belief as such, Buttelmann et al.’s findings can also be
explained with recourse to the notion of belief-like or knowledge-like states such as
acquaintance, engagement, or registration (Doherty, 2011; Apperly & Butterfill, 2009).
The child directs the experimenter in the false-belief condition to the second box because
the experimenter has not been acquainted with the fact that the object is now in this
box.
Another behaviour-based explanation might be: children expect people to look for
an object where they last saw it, as happens in the false-belief condition. So, they infer
that the agent is looking for the object and help him to get to it by pointing to the other
box. In the control condition, the agent is not looking where he last saw the object, so
he cannot be looking for the object but must have some other goal (to open the box he
is trying to open).
In Southgate et al.’s (2010) study, 17-month-olds watched an agent place two novel
unnamed objects in two separate boxes. Unbeknownst to the agent, the contents were
then switched. In Experiments 1 and 2, when the agent returned, she pointed to a box
(the incorrect box in the false-belief condition) and said: ‘Do you remember what I put
in here? There’s a sefo in here. There’s a sefo in this box. Shall we play with the sefo?’ In
the false-belief conditions, children correctly chose the item in the other box not the one
the experimenter pointed to. The authors’ interpretation is that children understood that
the experimenter wanted from the indicated box the object she thought was in there
and not the one that was actually in there. But whatever a mental-state rule can do to
prompt helping action a situation-action behaviour rule, ‘people want from a box what
was put in there in their presence’, can do as well.
Yott and Poulin-Dubois (pp. 156–171, 2012) and Thoermer, Sodian, Vuori, Perst, and
Kristen (pp. 172–187, 2012) adopt more sensitive approaches to differentiate between
interpretations. Yott and Poulin-DuBois taught 18-month-old infants a new rule to expect
that an object is not in the last place it was seen. Then, participants were administered
Editorial
7
a critical false-belief condition trial from Onishi and Baillargeon (2005). Yott and PoulinDubois reasoned that, if activation of behaviour rules plays a critical role then, after
learning the new rule, infants should also expect the agent in the false-belief trial to
search in the full box and not the empty box. The results indicated that infants looked
longer when the agent reached for the object in the full box compared to when she
reached in the empty box (replicating Onishi and Baillargeon). Yott and Poulin-Dubois
resist temptation to adopt a rich interpretation of their findings. The new rule was only
taught over a couple of trials and may not be sufficient to override the greater probability
of the general rule (built up over 18 months of learning) that objects are typically in the
last place observed.3
Yott and Poulin-DuBois (2012) also report limited inter-task coherence: infants’
duration of looking time in the false-belief trial (full box condition) marginally correlated
with infants’ ability to predict others’ unfulfilled intentions. Thoermer et al.’s (2012)
longitudinal study shows in one respect remarkable continuity. In unexpected-transfer
scenarios anticipatory looking at 18 months was strongly correlated (r = .50) with
children’s verbal predictions at 4 years (stayed significant even with verbal intelligence
partialled out). However, there was little correlation with verbal predictions on an
unexpected-contents task at 4 years. Even the correlation between the transfer and the
contents tasks at 4 years was remarkably low, which raises the suspicion that even
performance on the standard false-belief tests are dominated by shallow behaviour rules
rather than a coherent ToM. So, not only the infants’ but also 4-year-old children’s
reasoning system may lack the necessary degree of inferential integration for holding a
proper ToM as Rakoczy emphasizes.
Executive Function and Language
A popular argument for the negative-release approach for why children below 3 or 4
years fail the traditional false-belief test is that inhibition requirements in that task mask
conceptual competency. By taking away these inhibition difficulties, in the indirect
tasks reveals early ToM cognition in infants. Wang et al. (2012) compared implicit
anticipation and explicit prediction responses when the target object was present or
absent. Manipulation of object presence/absence had a rather small effect in the expected
direction on children’s explicit judgments. However, this effect was about the same (or
slightly larger) for the implicit anticipation measure. This finding poses a challenge
to explaining the dissociation between looking responses and verbal judgments by
claiming that direct tasks but not indirect tasks are subject to the distracting influence of
knowing reality. However, Wang et al. also found that separate measures of executive
functioning correlated with children’s direct judgments and not with their indirect visual
anticipations (regardless of executive demand – object present or absent), which does
speak to the possibility that direct judgments have executive demands that indirect
looking responses lack. A unifying solution for the study’s opposing messages might
be that there are alternative explanations for the link between traditional false-belief
3 The
teaching phase was not done with Onishi and Baillargeon’s (2005) set up for the false-belief test, which had a yellow
and a blue box; Yott and Poulin-Dubois’ (2012) rule-training task was done with an orange and blue box. The training may
not have taught a general behaviour rule (an object is not in the last place it was seen) but a fact about the orange box (i.e.,
that objects put inside end up in the blue box). But since the familiarization trials in the false-belief task followed Onishi and
Baillargeon, infants are still being taught in that set up that the object stays in the box where one last put (last saw) it. Yott
and Poulin-Dubois acknowledge such concerns and their rule-training approach will need improvement to better illuminate
the role of behaviour rules for explaining behavioural responses on the false-belief task.
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measures and executive tasks (Perner & Lang, 2000), for instance a common metarepresentational insight.
To the extent that visual anticipations reflect an implicit non-propositional mindreading system sensitive to ‘belief-like’ states (Surtees et al., 2012; Rakoczy, 2012), Wang
et al. (2012) suggest that the development of executive functioning partly helps make
emergent a later-developing explicit mind-reading system capable of ascribing mental
states with propositional content. However, the parallel onset of anticipatory looking
across different tasks does not exclude that it could be driven by preschoolers’ skills at
detecting statistical co-variation patterns (Ruffman et al., 2012).
Studying a population where executive function and explicit false-belief skills do not
develop at the same age as in normally developing children helps gain a clearer picture
of the developmental relationships between these measures. P. de Villiers and J. de
Villiers (pp. 188–209, 2012) compared oral deaf and hearing children’s performance on
deception and direct false-belief tasks in relation to executive function and complement
syntax mastery. Whilst both groups did not differ significantly in either their executive or
deception task performance (after controlling for their 11/2 year difference in age), the
deaf participants were significantly delayed on direct false-belief tests. In both groups,
hearing and deaf, false-belief understanding was strongly related to understanding saycomplements, but not to conflict inhibition, while deception was strongly related to
conflict inhibition but not say-complements. P. de Villiers and J. de Villiers discuss
that the responses to deception tasks – on a par with indirect looking responses
in false-belief tasks – can be handled by situation-action behaviour rules. Their view
is that complex language (measured with say-complements) allows representation of
propositional attitudes that enables passing the traditional false-belief test. Performance
on indirect false-belief tasks that escapes the requirements of linguistic propositional
representation is less sophisticated. This view gains some support from the finding
by Yott and Poulin-DuBois (2012) that 18-month-olds’ looking time on the violation-ofexpectation false-belief trial correlated with performance on a measure of inhibition, and
from the finding by Low (2010) that understanding complementation correlated with
preschoolers’ direct false-belief judgments but not their visual orienting.
Language can help with the emergence of belief-desire reasoning in other ways. San
Juan and Astington (2012) explain that language and executive function can interact to
bridge the gap between the time when children reason implicitly and when they reason
explicitly about false belief. Assuming that children start by implicitly representing
patterns of behaviour or belief-like or knowledge-like states, then repeated pairing of
epistemic verbs and/or their complement frames with those initial representations can
help children to abstract and remember the content of these representations, and to
uniformly encode and compare abstractions across contexts, leading to the formation
of explicit and generalizable representations. Generalizability is of core concern to
possession of mental concepts such as belief (Rakoczy, 2012; Vierkant, 2012). As such,
the acquisition of epistemic language supports performance on standard false-belief tasks
and, critically, cultivates meta-representational understanding.
Comparative Perspective
Couchman, Beran, Coutinho, Boomer, Zakrzewski, Church, and Smith (pp. 210–221,
2012) discuss how responses to doubt and uncertainty ground meta-cognition research
and, in turn, inform ToM research relating to self-awareness and consciousness. In
perceptual discrimination tasks with an option to opt-out of a primary task, dolphins
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and old world monkeys increased their opt-out responses in the same way as humans
did as discriminations became more difficult and success rate on the primary task
decreased. Granting these animals meta-cognitive abilities of attributing mental states
to themselves (see Carruthers & Ritchie, in press; Perner, in press-b, for a more cautious
interpretation) raises an interesting challenge for German and Cohen’s (2012) emphasis
on cue encoding. What are the cues that trigger meta-cognition, or are meta-cognition
and theory of other minds two distinct systems?
Of the non-human species argued to exhibit meta-cognition, few, if any, exhibit
false-belief understanding (Call & Tomasello, 2008). For Couchman et al. (2012), the
comparative evidence supports the hypothesis that meta-cognition emerged prior to
ToM. Cross fertilization has barely begun. Balcomb and Gerken (2008) used the opt-out
paradigm on 2 21 -year-old children and found earlier evidence of meta-cognition about
own ignorance than when children are asked directly (Rohwer, Kloo, & Perner, in press).
Meta-cognition (like false-belief understanding) may have primitive forms that precede its
explicit counterpart. Even so, Couchman et al. advise against simple categorical answers
when differentiating transitional forms of meta-cognition – uncertainty responses, whilst
defined as implicit, might have an emerging explicit mind producing them (see also
Vierkant, 2012).
Survival Pack: Glossary of Useful Distinctions
All contributions of this special issue centre around the question why very young children
and infants who consistently fail to show any understanding of belief on the traditional
direct false-belief test, nevertheless, do show some sensitivity to belief on indirect
measures. Before releasing the reader into the details of the assorted contributions,
we thought it helpful to give a last overview of all the different distinctions some of
which we have mentioned above and some will be encountered the first time in the
texts. Many come from outside Developmental Psychology (Consciousness Research
and Philosophy of Mind) and may be quite unfamiliar to many readers:
1. Unified body of knowledge – two (multiple) systems
Is the early understanding part and parcel of the later understanding or are early
and late understanding based on independent systems (bodies of knowledge)?
2. Implicit – explicit understanding
(a) Unconscious – conscious
(b) Procedural – declarative knowledge
Procedural knowledge can only be activated online when the relevant
situation occurs. Declarative knowledge enables conditional deliberation:
if a person were given wrong information she would believe . . .
(c) Non-conceptual – conceptual
Faced with two colour patches of slightly different hue, one can see the
difference, so one must represent the different hues but has no concept to
either express which is which or remember it, and so cannot judge whether
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Jason Low and Josef Perner
a later presented patch is of the same or a different hue. In contrast, if one
patch is blueish the other reddish, then I can express the difference and
remember it.
(d) Automatic – spontaneous – controlled
When something (knowledge, action) tends to be triggered (e.g., what
another person believes) by a certain situation then we can distinguish the
following cases. If it is automatic, it is difficult or impossible to prevent it from
being triggered. If it is spontaneous, it can be stopped at will. Con trolled
knowledge or action is not triggered spontaneously but needs to be willed.
3. Innate – learned
The content of innate knowledge is provided by the genes, although it probably
needs interaction with the environment to be activated. Learned knowledge gets
its content and structure from the structure of the experienced environment.
4. Modular – central process
The two most important features (see Fodor, 1983 for complete list) of modular
processes is that they contain knowledge that is available only for the process
(encapsulation) and cannot be altered by having knowledge to the contrary
(impenetrability), for example, the lines of the Müller–Lyer illusion still look
different even when one knows that they are the same length. Central processes,
in contrast, contain knowledge that can be altered by new information and can be
used for discussion.
5. Causally shallow – deep understanding (behaviour rules – mental state rules)
Behaviour rules encode causal dependencies of future behaviour on behaviour in
a current situation. This is a shallow causal link between two observables. Mental
state rules provide a deeper understanding of how this causal connection works:
the current situation creates a mental state in the individual, which then causes
the individual to act in the predicted way.
6. Law-like (nomic) generalization – reasons for acting
Nomic generalizations provide knowledge (of how people will act) that is based on
existing regularities (abstracted from observation or given by evolution). Reasons
for acting provide insight into what a person should do in a given situation and,
therefore, most likely will do so.
A word of caution: these distinctions are often seen as packages. For instance,
behaviour rules (because of their unfortunate association with ’behaviourism’) are taken
to be learned while a ToM, especially when combined with modularity, is taken to
be innate. We advise to resist tacit assumptions of this kind: behaviour rules could be
provided innately by evolution, while a ToM could be acquired through experience
(theory formation). With this advice, off you go!
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Received 22 December 2011