Tim P. German

Two reasons to abandon the false belief task as a test of theory of mind

The false belief task has often been used as a test of theory of mind. We present two reasons to abandon this practice. First, passing the false belief task requires abilities other than theory of mind. Second, theory of mind need not entail the ability to reason about false beliefs. We conclude with an alternative conception of the role of the false belief task.

Representational and executive selection resources in ‘theory of mind’: Evidence from compromised belief-desire reasoning in old age

Effective belief-desire reasoning requires both specialized representational capacities-the capacity to represent the mental states as such-as well as executive selection processes for accurate performance on tasks requiring the prediction and explanation of the actions of social agents. Compromised belief-desire reasoning in a given population may reflect failures in either or both of these systems. We report evidence supporting this two-process model from belief-desire reasoning tasks conducted with younger and older adult populations. When task inferential complexity is held constant, neither group showed specific difficulty with reasoning about mental state content as compared with non-mental state content. However, manipulations that systematically increase executive performance demands within belief-desire reasoning caused systematic decreases in task performance in both older and younger adult groups. Moreover, the effect of increasing executive demands was disproportionately greater in the older group. Regression analysis indicated that measures of processing speed and inhibition contributed most to explaining variance in accuracy and response times in the belief-desire reasoning tasks. These results are consistent with the idea that compromised belief-desire reasoning in old age is likely the result of age-related decline in executive selection skills that supplement core mental state representational abilities, rather than as a result of failures in the representational system itself.

Functional Fixedness in a Technologically Sparse Culture

Problem solving can be inefficient when the solution requires subjects to generate an atypical function for an object and the objects typical function has been primed. Subjects become “fixed” on the design function of the object, and problem solving suffers relative to control conditions in which the objects function is not demonstrated. In the current study, such functional fixedness was demonstrated in a sample of adolescents (mean age of 16 years) among the Shuar of Ecuadorian Amazonia, whose technologically sparse culture provides limited access to large numbers of artifacts with highly specialized functions. This result suggests that design function may universally be the core property of artifact concepts in human semantic memory.

Immunity to functional fixedness in young children

In thecandle problem (Duncker, 1945), subjects must attach a candle to a vertical surface, using only a box of tacks and a book of matches. Subjects exhibitfunctional fixedness by failing, or being slow, to make use of one object (the tack box) as a support, rather than as a container, in their solutions. This failure to produce alternate functions is measured against improved performance when the tack box is presented empty rather than full of tacks (i.e., not preutilized as a container). Using an analogous task, we show that functional fixedness can be demonstrated in older children (6- and 7-year-olds); they are significantly slower to use a box as a support when its containment function has been demonstrated than when it has not. However, younger children (5-year-olds) are immune to this effect, showing no advantage when the standard function is not demonstrated. Moreover, their performance under conditions of preutilization is better than that of both older groups. These results are interpreted in terms of children’s developing intuitions about function and the effects of past experience on problem solving.

Function and the Origins of the Design Stance

We report 2 experiments addressing childrens developing understanding of design. Experiment 1 showed that although 5-year-old children judged an objects function according to its original design rather than a subsequent accidental activity, design was not preferred over a subsequent intentional use. Adults select the design function in both cases, suggesting that childrens initial assignment of function is based on any intended goals for which the object is used. Experiment 2 compared assignment of function with object categorization, demonstrating that although 5-year-old childrens assignment of object function is based on any goals associated with the object, their categorization is adult-like and based on the category intended by the objects creator (over a category assigned by another agent). We conclude that preschoolers appreciate the link between creators and categories before constructing a design stance supporting reasoning about artifact functions.

Children's counterfactual inferences about long and short causal chains

Recent findings on counterfactual reasoning in children have led to the claim that children’s developing capacities in the domain of ‘theory of mind’ might reflect the emergence of the ability to engage in counterfactual thinking over the preschool period (e.g. Riggs, Peterson, Robinson & Mitchell, 1998). In the study reported here, groups of 3- and 4-year old children were presented with stories describing causal chains of several events, and asked counterfactual thinking tasks involving changes to different points in the chain. The ability to draw successful counterfactual inferences depended strongly on the inferential length of the problem, and the age of the children; while 3-year-olds performed above chance on short inference counterfactuals, they performed below chance on problems involving longer inference chains. Four-year-old children were above chance on all problems. Moreover, it was found that while success on longer chain inference problems was significantly correlated with the ability to pass tests of standard false belief, there was no such relationship for short inference problems, which were significantly easier than false belief problems. These results are discussed in terms of the developmental relationships between causal knowledge, counterfactual thinking and calculating the contents of mental states.

Children's inferences from 'knowing' to 'pretending' and 'believing'

Threestudiesinvestigatedchildren’sabilitytodrawinferencesfromthepropertiesof one mental state to the properties of another. Inferences fromknowledge/ignorance to the possible contents of pretends and beliefs are crucial to developing a representational theory of mental states. In Experiment 1, we replicated Lillard’s (1993) finding that 4- and 6-year-olds fail to appreciate that a character who does not know about an entity cannot pretend to be that entity. We show that these children also fail a similar task in which the inference to be made is from not knowingto thinking (false belief). Lillard’s inference tasks may be difficult because of their performance demands—specifically, children are not offered a plausible alternative content for the agent’s pretence or belief state. In a second experiment, children were presented withknow‐pretend and know‐think inference tasks which offered two options for the content of a character’s mental state. One option was consistent with that character’s knowledge state, while the other was not. Under theseconditions,4- and6-year-oldchildren’s performanceimprovedsignificantlyon both pretend and think. Athird experiment investigated the role of the salience of thecharacter’s ignorance andthepossibleuseof anassociationstrategyinproducing successful performance in Experiment 2. When the salience of the character’s ignorance was reduced, children still succeeded on know‐pretend inferences but failed on know‐think inferences. These results suggest that children do not really graspthe theory of mental representation. The results better support the ToMM-SP model of‘theoryof mind’development.Accordingtothis model,conceptpossession is prior to, and therefore does not depend upon, knowledge of theories, and task success depends upon the control of salience. Thefunctionof ‘theory of mind’ ability isto provideinterpretationsof thebehaviour of agentsintermsof theircognitiveproperties(Leslie, 1994b).It iswidelyagreedthatthis abilityrequirespossessionof mentalstateconceptssuchas ‘belief’, ‘desire’and‘pretend’. A major topic of debate over the last 15 years has been how to account for the acquisition of these concepts. Where do these highly abstract concepts come from and

Conditions under which function information attenuates name extension via shape.

Children often extend names to novel artifacts on the basis of overall shape rather than core properties (e.g., function). This bias is claimed to reflect the fact that nonrandom structure is a reliable cue to an object having a specific designed function. In this article, we show that information about an objects design (i.e., about its creators intentions) is neither necessary nor sufficient for children to override the shape bias. Children extend names on the basis of any information specifying the artifacts function (e.g., information about design, current use, or possible use), especially when this information is made salient when candidate objects for extension are introduced. Possible mechanisms via which children come to rely less on easily observable cues (e.g., shape) and more on core properties (e.g., function) are discussed.

No (social) construction without (meta-)representation: Modular mechanisms as a basis for the capacity to acquire an understanding of mind

Theories that propose a modular basis for developing a “theory of mind” have no problem accommodating social interaction or social environment factors into either the learning process, or into the genotypes underlying the growth of the neurocognitive modules. Instead, they can offer models which constrain and hence explain the mechanisms through which variations in social interaction affect development. Cognitive models of both competence and performance are critical to evaluating the basis of correlations between variations in social interaction and performance on mental state reasoning tasks.