Knowing without knowing: implicit cognition and the minds of infants and animals / Saber sin saber: la cognición implícita y las mentes de niños pequeños y animales

Abstract The main aim of this paper is to highlight the need to address the conceptual problem of ‘implicit knowledge’ or ‘implicit cognition’ — a notion especially important in the study of the nonverbal minds of animals and infants. We review some uses of the term ‘implicit’ in psychology and allied disciplines, and conclude that conceptual clarification of this notion is not only lacking, but largely avoided and reduced to a methodological problem. We propose that this elusive notion is central in the study not only of animal and infant minds, but also the human adult mind. Some promising approaches in developmental and evolutionary psychology towards innovative conceptualization of implicit knowledge remain conceptually underdeveloped and in need of reconsideration and re-elaboration. We conclude by suggesting that the challenge of implicit cognition and nonverbal minds will only be solved through a concerted interdisciplinary approach between psychology and other disciplines.

Davidson is speaking here not only of animals, but also of human infants (although he concedes that human infants might be a special case because they will eventually become speakers and therefore rational creatures). His argument is that to be rational a creature needs to possess 'propositional attitudes'beliefs, desires, intentions …and you cannot have these without language. Attributing to nonverbal creatures such propositional attitudes may help us understand their behaviour, just as attributing to a missile the desire to reach a target may be a good way of glossing its behaviour. However, Davidson argues, just as this does not mean that the missile has any actual desire to hit a target, animals and infants may have no actual beliefs, desires and intentions even if at some level they behave as if they had them.
This claim, made in a 1982 paper, may seem surprising to comparative and developmental psychologists, because these branches of psychologythose that are more directly concerned with the minds of creatures that cannot speak about their thoughts and experiencesseemed to have firmly established in the first half of the twentieth century that animals and infants are intelligent creatures and therefore capable of some forms of complex thought.
For example, the famous experiments of Köhler (1917Köhler ( /1921 with chimpanzees in Tenerife demonstrated an ability to solve problems in a flexible and creative way (for instance, by using tools to reach a previously inaccessible food), going beyond the simple repetition of past, positively reinforced experiences. Köhler proposed that the chimpanzees demonstrated 'insight', i.e., some form of intelligent understanding of the situation and an ability to generate innovative responses to solve problems. Even more importantly, when the chimpanzees failed to solve problems, they rarely did so in a random way. Frequently, they behaved as if they had an erroneous understanding of the situation (for example, acting as if they assumed that a box could stick to a wall when they needed it in a higher position to climb and reach a target). These sorts of errors suggested that even if their understanding was incorrect or incomplete, they were somehow 'thinking' about the problem and its potential solution. To take a term coined by Köhler himself, they were demonstrating 'Folk physics', although maybe a simian version that may be different from human 'Folk physics'.
Similarly, the pioneering work of Piaget (1936Piaget ( , 1937 in developmental psychology established that in humans intelligence indeed starts before language: during their first two years of life infants possess what he called a 'sensorimotor' or practical intelligence, i.e., an ability to 'think' in action, and he suggested that the symbolic and operational intelligence of older children and adults is built upon these early sensorimotor foundations. As with chimpanzees, when infants committed mistakes, these consisted of systematic errors, as if provoked by ways of understanding and thinking about the world that are different to the adult ones, but involve genuine intelligence. Think, for example, of the famous object search mistakes that led Piaget to propose that young infants do not have a notion of object permanence like adults, which makes them entertain different expectations about the nature of objects and where they can be found in the external world. Later work in both comparative and developmental psychology might appear to have reinforced the idea of complex early nonverbal thought in both evolution and development. For example, not only our close relatives, chimpanzees, but also animal species that are more distant evolutionary relatives of humans, such as ravens and crows, behave in seemingly intelligent ways (such as using tools or deceiving others). This has led some comparative psychologists to suggest that some forms of 'thought' may be evolutionarily very ancient or that they can emerge through convergent evolution in brains that are very different to those in the human lineage (Emery, 2004). On the other hand, contemporary developmental psychology, by means of new sophisticated non-verbal research methods, has suggested the existence of even more complex cognition in very young infants than Piaget's limited observational methods and theoretical assumptions revealed. For example, we now know that, before being able to manually retrieve hidden objects, infants seem to understand that they still exist and where they exist, thereby demonstrating a surprisingly rich ability to represent the world (Baillargeon, Spelke, & Wasserman, 1985).
Over-attributing nonverbal thought? Such claims about animal and infant intelligence have not gone unchallenged. The early claims of 'insight' in chimpanzees were disputed by behaviourist psychologists who believed in the power of associative learning to explain problem solving without having to invoke forms of nonverbal thought (Boakes, 1984). Of course, ultimately, the aim of at least some radical behaviourists was to reduce even verbal thought to covert responses (Skinner, 1957). Nowadays, even if not radical behaviourists, some authors still question claims about the degree of thought and intelligence that animals need in order to do the apparently complex things that they demonstrate. The suggestion is that even if animals are just deploying an ability to learn contingencies and extract regularities in more complex ways than suggested by early behaviourist psychologists, in the end they do so without achieving any real understanding or thinking with abstract concepts such as other minds or causality. For example, Povinelli (2000) criticizes the interpretation of chimpanzee tool use as proof of understanding of physical causation because the errors that chimpanzees systematically commit in practical tasks suggest that they may be only attending and reacting to the external appearances of things, without deploying any real understanding of or ability to reason about abstract unobservable notions such as force, weight, etc., which, according to him and his colleagues, constitute the defining feature of human thought and reasoning (Penn, Holyoak, & Povinelli, 2008).
This type of criticism has been applied not only to feats of physical intelligence, but also to social cognitive skills, especially those that fall under the umbrella of 'Theory of mind' (the ability to think about the mental states of others or oneself)an area of intense research in comparative and developmental psychology over the last few decades. For example, some authors claim that the common primate ability to follow the gaze of others to look at the same object may reveal an ability to understand that the gazer is 'seeing' something, and therefore prove some degree of 'Theory of mind' However, authors like Povinelli (2000) (see also Penn & Povinelli, 2013) again suggest that there need be no 'thinking about thought' here, as the reaction to look in the same direction as others may occur as a simple reflex or a learned response to observable stimuli (the physical orientation of the others' eyes and face). Of course, even some authors who accept something like this line of criticism maintain that primate behaviour may require sophisticated understanding and reasoning, while insisting that this understanding and reasoning is about behaviour rather than psychological states (Penn & Povinelli, 2013). But others may find that the critics' strategy diminishes their confidence that non-human primates understand or reason at all; after all, the sort of associative mechanisms typically invoked to account for learning to react to observable contingencies does not invite much talk about thinking in any 'proper' sense of the word.
In recent years some authors have suggested that these deflationary accounts of apparently complex behaviour applied to animals could be extended to the seemingly sophisticated cognition of human infants. For example, a recent debate in developmental psychology concerns the age at which children demonstrate one of the key skills constitutive of Theory of mindunderstanding false beliefs, or that people will act guided by their representations even when these do not match objective reality. Until recently, empirical findings clearly indicated that a full-fledged theory of mind, with the ability to understand the key notion of false belief, was available only at around 4-5 years of age, and quite likely linked directly or indirectly to the process of language acquisition and linguistic communication (Astington, 1993;Wellman, 2014). However, in the last 20 years a wave of experiments with very young infants, using nonverbal versions of false belief tasks, has demonstrated a remarkable 'sensitivity' to the beliefs of others at surprisingly early ages (6-12 months), before language starts to emerge and even before some ToM skills traditionally considered to be cognitively simpler (for example, gaze following) are fully consolidated (see, for example, Baillargeon et al., 2010, for a review). These findings suggested that complex thought about abstract, unobservable entities such as beliefs and mental states in general may be entertained by infants who are still far from possessing even a minimal amount of linguistic ability and who are still very underdeveloped in other aspects of cognition.
The perceived implausibility of this claim led some authors (e.g., Perner, 2010) to turn to comparative psychology, specifically to Povinelli's objections about animal Theory of mind and animal thought in general, and try to apply them to human infants and the rich interpretations of recent experimental findings. The debate is about whether this apparent sensitivity to false belief is based upon a genuine ability to represent and reason about the beliefs of others, or rather upon some adaptive system that does not rely on the representation of others' thoughts and therefore cannot be said to be a genuine Theory of mind that supports reasoning about mental states.
For example, infants might be relying upon the use of learned behaviour rules (e.g., people tend to return to the places where they have left an object) without the need to process and think about the mental states (representing the object location) that explain such behaviour. Although it is not always the aim of critics to deny the possibility of thought and intelligence in young infants and animals, such behaviour rules may be learned without the need to engage in 'proper' thinking or reasoning, since they might be based upon the mere detection of contingencies between observable behaviours. Therefore these explanations, even unwittingly, put into question the thinking capacities of infants and animals. If there is no 'true' Theory of mind or no 'true' understanding of causality behind the adaptive responses of primates and infants, then maybe what they are doing is not really thinking and reasoning 'properly' speaking.

Implicit thought?
A common way in which authors in favour of animal and infant thought try to counter the above criticisms is by claiming that the sort of understanding and thinking demonstrated by young infants and animals is 'implicit', in contrast with the 'explicit' understanding and reasoning displayed by human adults (e.g., Low & Perner, 2012). Thus, whereas adults and older children demonstrate some sort of explicit folk theories about how things work (e.g., they can linguistically explain to different extents why they think that an object balances on top of another in a particular position, or why people can or cannot see an object depending upon whether it is or not in their line of sight), infants and some nonhuman animals would possess only an implicit understanding of physical and mental mechanisms, which they can reveal only in action. Thus, chimpanzees who follow gaze would have only an 'implicit' understanding of the mental states of seeing and attention, and young infants who take into account others' false beliefs would do so only by means of some implicit representation of those beliefs.
There is, however, a huge problem with such notions of implicit understanding and thought, and it is that typically they themselves remain unsatisfactorily implicit and intuitive. In contrast with how easily and frequently the notion of implicit knowledge is invoked, detailed attempts at defining what is meant by implicit thought remain very rare, and such attempts as have been madefor example, in the philosophical literature on 'tacit' knowledge (Davies, 2015) have rarely (if ever) proved useful in explaining animals' and young children's success in tasks designed to test for causal reasoning and theory of mind. This lack of definition and consensus about what is meant by implicit thought processes is, in our view, one of the key unsolved challenges of psychology and cognitive scienceone that may be crucial for understanding not only the cognition of nonverbal creatures, but also the adult human mind. Indeed the notion of implicit thought processes has been applied not only to animals and infants, but also to adults who frequently appear to be able to perceive and compute information without awareness of what they are doing and without being able to report how they are doing it.

From unconscious inferences to implicit cognition
The problem of implicit knowledge in adults is certainly not new. It can be traced back to the very origins of scientific psychology, for example to the notion of 'unconscious inference' formulated by von Helmholtz (1867) to explain human perception. Building on examples of visual illusions, such as the illusion of the movement of the sun, he argued that these must be provoked by the operation of 'an involuntary, pre-rational and reflex-like mechanism which is part of the formation of visual impressions', and that cannot be overridden by our rational and conscious knowledge. These unconscious inferences, far from being an exception to explain just some visual illusions, would be responsible for our everyday perception of the real world as a reality out there, in front of us, made of objects that we can see and touch. Unconscious inferences are like interpretations that are 'urged upon our consciousness' and upon which we have no control, and no conscious knowledge of how they occur. In the words of Helmholtz himself: … it may be permissible to speak of the psychic acts of ordinary perception as unconscious inferences, thereby making a distinction of some sort between them and the common so-called conscious inferences. And while it is true that there has been, and probably always will be, a measure of doubt as to the similarity of the psychic activity in the two cases, there can be no doubt as to the similarity between the results of such unconscious conclusions and those of conscious conclusions. (von Helmholtz, 1867, p. 4) Helmholtz identifies here a key problem of any notion of implicit knowledge: to what extent is it the same 'psychic activity' as in explicit knowledge but just without awareness of the activity, and to what extent is it a completely different way of knowing things?
Although Helmholtz's unconscious inferences did not capture the imagination of the first experimental psychologists, who were suspicious of an idea that looked like an oxymoron ('since an inference is ostensibly a conscious process and can therefore be neither unconscious nor immediate, [Helmholtz's] view was rejected as self-contradictory' [Boring (1942, p. 289)], notions of implicit cognitive processes in adults have kept re-emerging in psychology and related disciplines, such as philosophy and linguistics.
For example, the philosopher Ryle (1945-6) introduced a distinction between 'knowing that' and 'knowing how', in an attempt to denounce the fundamental mistake of 'equating exercises of intelligence with acts of theorising'. His (philosophically) radical suggestion was that not only 'knowing that' (i.e., discovering truths or facts and contemplating them in propositional format) co-exists with 'knowing how' (i.e., discovering ways and methods of doing things), but also that 'knowing how' is logically prior to, and cannot be defined in terms of 'knowing that'. Although Ryle neither uses the term 'implicit', nor refers to the psychological notions of practical intelligence (Piaget) or Insight (Gestalt), his distinction bears a clear similarity to the idea of an implicit form of knowledge somehow contained in the ability to do intelligent things, rather than explain or talk about them.
In linguistics, Chomsky (1965) made use of a notion of 'tacit knowledge' to explain how speakers seem somehow to tacitly know the rules of the generative grammars of their language, even if they may be completely unable to formulate such rules in any explicit waya notion that had important resonance across the cognitive sciences (see Davies, 2015, for a recent review).
In psychology a new wave of appeal to implicit cognition took momentum in the 1980s and 1990s when psychologists in a variety of areas (memory, perception, reasoning, learning) felt they had clear evidence of the existence of 'implicit cognition', by which they mainly seemed to mean knowledge demonstrated in behaviour but of which we are not aware (e.g., Underwood, 1996). For example, and directly inspired by Chomsky's notion of tacit knowledge of grammatical rules, experiments on the learning of artificial grammars had been running since the 1960s showing that people exposed to example strings of 'grammatical' constructions (syllable strings) in an artificial language were later capable of telling which of a set of new strings were correct and which incorrect, even if they were unable to explicitly identify the rules that they were using, and that they seemed to have unconsciously extracted from the examples.
Another area where the concept of 'implicit cognition' had a special impact was social psychology. Social psychologists found a wealth of experimental results suggesting 'automatic and unconscious processes underlying judgments and social behavior', (Payne & Gawronski, 2010, p. 1) and put them under the umbrella of 'implicit social cognition'. An example of a typical social cognitive effect is the demonstration that prejudices that participants may not explicitly endorse (e.g., 'African Americans are more violent than white Americans') may however affect their behaviour in practical tasks. Thus in a shooting game, in which subjects must decide whether to shoot or not a potentially armed individual, more wrong shooting decisions are taken when the target is African American and this happens even for African American participants themselves who genuinely reject the stereotype (Correll, Park, Judd, & Wittenbrink, 2002). These effects are seen by social psychologists not only as unconscious, but also automatic, inescapable and in conflict with explicit declarations, which summarizes very well the type of features that lead psychologists to claim that there is implicit cognition (Payne & Gawronski, 2010).
With the recovery of the notion of implicit knowledge into mainstream psychology, driven by the accumulation of empirical evidence, the accompanying unsolved conceptual problemwhat are the mechanisms and features of implicit thought and knowledge?has inevitably come back. Is it just normal thought without consciousness and without the possibility of verbal report? Or is it a different way of knowing and reasoning about things, subserved by different mechanisms?
One option, taken in one way or another by a majority of authors, is to acknowledge that there is a problem (lack) of definition of implicit cognition, and then move on and concentrate the discussion on the methodological, rather than the conceptual challenges of the notion. Thus, in his Preface to the 1996 edited book Implicit Cognition, Geoffrey Underwood equates implicit knowledge to the problem of not being conscious of processing information, and points out that 'animals without consciousness can learn, and so they are learning by definition implicitly'. However, when dealing with the problem of how we can tell if an animal or another person is conscious, he recommends to avoid stepping on a path that is 'reserved to philosophers' and to concentrate on empirical methodological problems, avoiding conceptual issues about what is perception without awareness, learning without knowing or implicit knowledge itself. The implication seems to be that the proper task of psychologists is methodological: finding tasks and measurable behaviours that they can use to decide if a piece of knowledge should be labelled explicit or implicit. But as the rest of the book shows, even with such objective measurements, the scope of disagreement among psychologists working on implicit cognition in their interpretations of what counts as implicit or explicit is such that there should be little doubt that the key underlying problem is as conceptual as it is methodological, and there seems to be little to be gained from trying to keep it within the confines of different disciplines. The two-system approach One of the more interesting current developments emerging from the implicit cognition revival in psychology is the idea of dual processes or two-system approaches to cognition. In this view, adult human reasoning would be the result of the operation (and, depending on the view, co-operation or competition) of two different types of mental processes: implicit processes, which are fast, efficient, but inflexible; and explicit processes, which are slower, less efficient, but more flexible (e.g., Evans, 2003). Interestingly, this proposal comes frequently accompanied by the assumption that implicit processes are those that we share with animals, and therefore quintessentially nonverbal, whereas the explicit systems are specifically human, and maybe somehow linked to linguistic minds. Whether verbal or nonverbal, implicit or explicit, one apparent assumption of at least some two-system approaches is that both types of processes can be considered as different, but genuine forms of reasoning and thinking, and in this they could connect well with the developmental and comparative traditions (Piaget and Insight) that we mentioned earlier.
However, when one looks a little deeper at the conceptual characterization of the two-system distinction, the familiar problem of lack of definition and specification resurfaces. For example, in social psychology a two-system approach proposes that we typically deal with tasks and problems of our everyday life using, on the one hand, Associative processes (implicit), and on the other Rulebased processes (explicit) (Smith & DeCoster, 2000) or Associative vs Propositional processes (Strack & Deutsch, 2004). These processes are postulated to be genuinely different: they consist of different psychological operations and have different properties, even if our everyday behaviour is in the end the result of an interaction between them.
Thus, in the above example of the shooting game, the Associative processes would automatically activate the representation of the more violent African American stereotype that we all know, whether we endorse or hate that stereotype. In some tasks that require a quick decision (e.g., to shoot or not to shoot when someone appears holding something that could be a gun in their hand) the very fact that this is activated will inevitably prime by association a particular type of response. However, if one has the time to 'think' about the requirements of the task and ponder the possibilities, the response will be the result of different processes, which may inhibit or make a more elaborate use of the information highlighted by the automatic associations.
The problem with these interpretations of how implicit cognitive systems work is that it is difficult to see in what sense they would constitute a type of knowledge. This version of the two-process or two-system option might appear to amount to just a return to the contrast between associative processes and intelligent, higher cognitive processes. In this respect, if the associative processes are all that there is to 'knowing implicitly', then although a theorist may come to formulate rules and principles that describe a subject's behaviour, it is unclear that the subject herself knows these rules and therefore that they form part of the mechanisms that explain her behaviour (Quine, 1970). To use a more extreme example, the wing of a bird does not possess knowledge of the aerodynamics of flight, but reflected -'implicit'in its design there is a lot of aerodynamic knowledge. The wing itself is just a biological artifact selected by evolution to do a particular job, and it does this job without being driven by any knowledge in any interesting sense of the term.
If we return to the issue of implicit knowledge in nonverbal creatures, Perner and Roessler (2012), in one of the few attempts at addressing directly the problem of what is meant by 'implicit knowledge', make a very similar criticism in relation to the claim that infants may have implicit understanding of false belief. They argue that if young infants passing FB tests are just following a rule of the type 'people return to the place where they last saw an object', the term 'implicit' here would not really refer to any mentalistic mechanism used by the child, but rather to the fact that an external observer with ToM can see why the rule captures the causal role of representations in behaviour, but the rule itself needs not incorporate any mentalistic knowledge. Heyes (2014) has recently extended this sort of alternative, sub-mentalistic explanation to much of what not only young infants, but also adults, do in their everyday social life without need to resort to specialized mentalistic knowledge.
Approaches like these use the term 'implicit' not to refer to genuine knowledge, but to alternative adaptive systems. And indeed, if this is what there is to implicit knowledge, then it does not seem to be a very interesting notion epistemologically.

True implicit knowledge
We believe, however, that there is a different way of conceiving of implicit knowledgea genuine way of knowing something which is neither just a matter of associative learning nor fully explicit and verbalizable reasoning. This is the type of knowledge that evolutionary and developmental psychologists have been trying to capture with notions such as practical intelligence, procedural knowledge or insighta form of understanding the physical and social world that is different from verbal propositional reasoning, but also different from blind trial and error or associative behavioural rules. We believe this is the most important sense in which the term implicit has been used and the one that deserves to become a primary goal of research.
The challenge that psychology, philosophy and associated disciplines have not yet met is thisto provide a convincing notion and analysis of what implicit or practical reasoning or thinking could consist of.
We believe that this challenge can be best addressed from a comparative/ developmental perspective in a cross-disciplinary dialogue with philosophers, linguists and other disciplines, which tackles the problem of nonverbal thought in nonverbal minds. It has indeed been developmentalists and comparative psychologistsfaced with the challenge of accounting for intrinsically nonverbal thought (transiently so in the case of human infants)who have provided some of the most interesting attempts at characterizing implicit thought as a genuine reasoning process that does not make use of language or other propositional thinking tools.
We have already referred to the early efforts of Köhler and Piaget, with their notions of insight and dynamic systems of coordinated motor and perceptual schemas. Such notions have admittedly remained intuitive and elusive, somewhat devoid of conceptual specification and substantiation. However, a way forward in our attempts to characterize implicit knowledge may consist of revisiting and redeveloping these early notions using some of the conceptual tools that have emerged since the time they were formulated. One such tool is connectionist or neural network modelling, as exemplified by Karmiloff-Smith (1992) in her model of representational redescription, where developing humans move from procedural implicit knowledge (knowing how to do thingsher version of Piagetian sensorimotor intelligence) to different degrees of explicit knowledge. Karmiloff-Smith provides a tentative analysis of the problem of the format in which implicit knowledge occurs and how it differs from explicit forms of knowledge, and suggests that connectionist networks may be the best model of how procedural knowledge may work and what it might consist of.
Other promising exploratory avenues are emerging in relation to the problem of mentalistic attribution in animals and young infants. For example, it has been suggested that the nonverbal understanding of how other agents relate to the world might be achieved through the perception and representation of 'intentional agentobject relations' coded as Gestalt-like perceptions of intentionality (Gómez, 2008) that would be independent of any verbal or propositional coding of such relations. And from within the two-system approach to the implicit/explicit distinction, Apperly and Butterfill (2013) have provided a tentative account of what an implicit system of nonverbal, implicit mentalistic computations could look like, and how it would differ from the simple coding of behavioural rules or associations. They postulate a set of basic mental state attributions (e.g., 'Registration'), different to the familiar propositional attitudes that inform explicit mentalistic processes, and that could account for the fast and efficient, but limited mentalistic computations of young human infants, animals and adults in situations that demand quick, automatic responses.
It is still too soon to evaluate if attempts like these are succeeding in advancing our understanding of implicit knowledge and nonverbal minds, but they have in common an important featurethey do try to address the conceptual challenge of tackling implicit knowledge as a true type of knowledge, and the use of deep interdisciplinary interaction as a research toola genuine search for innovative concepts that fill the gap between associative learning and propositional cognition.
Conclusion: accepting the challenge of implicit knowledge Chomsky once said that in science there are problems and there are mysteries (Chomsky, 1975), and although we can aspire to scientifically unravel the former, this is not the case for the lattermysteries will remain outside the reach of scientific explanation. Hopefully implicit knowledge is not a mystery, but a problem that we can aspire to solve scientifically. However, it looks as if at the time we can only point at the need for a genuine notion of what it is to implicitly know something and some potential exploratory avenues of where to look for the conceptual innovation necessary to tackle the challenge.
We believe that this is one of the great unsolved problems of psychology and philosophy, and one whose solution may not only help us understand the minds of nonverbal creatures such as infants and animals, but also our own adult minds, as implicit knowledge may be at the very basis of what it is like to understand something vs. merely knowing it explicitly. Solving this problem is all the more urgent as an increasing amount of research literature proposes and relies on this notion without offering definitions or conceptual analysis.
The main aim of this paper has been to highlight the need to address this problem that has largely been sidestepped by psychology and its allied disciplinesthe nature of 'implicit knowledge' and what we argue is the closely related, maybe largely identical, problem of the nature of knowledge in nonverbal minds. We have pointed out the lack of appropriate concepts to account for the intuitive idea that we know things in non-explicit ways; we have suggested that some promising approaches towards innovative conceptualization of knowing implicitly lie in some early efforts of comparative and developmental psychologists, which however remained conceptually underdeveloped but may benefit from a reconsideration in the light of current advances, such as connectionist simulations. We have concluded by suggesting that the time has come for a concerted interdisciplinary approach between psychology and other disciplines to tackle this key conundrum.
La aparente implausibilidad de esta idea dio lugar a que algunos autores (por ejemplo, Perner, 2010) recurriesen a a una psicología comparativa, específicamente a las objeciones de Povinelli relativas a la Teoría de la Mente y el pensamiento animal en general, e intentaran aplicarlas a los niños pequeños humanos y a las generosas interpretaciones de los hallazgos experimentales recientes. El debate versa sobre si esta aparente sensibilidad a la falsa creencia se basa en una capacidad real para representar las creencias de otras personas y razonar sobre ellas, o más bien en algún tipo de sistema adaptativo que no depende de la representación de los pensamientos ajenos y que, por tanto, constituye una genuina Teoría de la Mente que permita razonar sobre estados mentales.