2. development of theory of mind

theory of mind

• The insight that people hold mental states and that these govern behaviour 

• Mental states – e.g. belief, desire, goals, etc..  

• Allow us to make sense of the social world – to predict and explain people’s actions 

desire based ToM

• People’s desires are idiosyncratic and constantly changing 

• Do children understand that other people may have desires that differ from theirs? 

• 18m but not 14m understood that the experimenter’s desired food differed from theirs 

• Suggests they understand that desire is a subjective mental state that can differ from person to person 

belief based ToM

• Distinction between mind/world 

• Requires understanding that a person has a representation of the world, which may be different from the world itself or from our own perception 

• Shift from a situation-based to a representation-based understanding of behaviour 

testing ToM

• False belief task  

• Tests whether child can represent what another person believes in contrast to their own beliefs or reality 

false belief tasks

Unexpected transfer task also known as the Maxi chocolate task (Wimmer & Perner, 1983); and the Sally-Ann task (Baron-Cohen, Leslie & Frith, 1985) 

Deceptive box task also known as the Smarties task (Gopnik & Astington, 1988) 

true belief task

tests whether child can represent what another person believes when that belief matches their own beliefs or reality

deceptive box perner

• What is inside this tube? (guess) 

• What is in it? (see) 

• What will your friend xxx say is inside? (predict) 

deceptive box gopnik

• When you first saw this tube, before we opened it, what did you think was inside? 

• 3-4yr old difficulty acknowledging  false belief in others and own prior false belief once know what is inside 

• Demo of deceptive box task 

interpreting findings

• 3-year-old children usually fail False-Belief tasks 

• 4-year-old children usually pass False-Belief tasks 

• Traditionally taken as evidence that around this time children ‘acquire’ a theory of mind 

• I.e. Radical conceptual shift and stage-like development around 4 years 

ToM natural conversation

• Shiri: I wonder if bunny ate all her cookie. 

• Maya (2y4m): No, bunny not got cookie, Moz got cookie. 

• Shiri: Ok.. Let’s go to your room to see. 

• Shiri: (on entering M’s room) Look, bunny has the cookie. I was right! 

• Maya: Yeah. I thought Moz got the cookie!  

i.e. Spontaneously reflected on her own previous false belief  

do 3 yr olds not have ToM

• Lack of positive evidence doesn’t necessarily mean lack of competence  

• Performance limitations masking children’s competence? 

  • Problem with language? 

  • temporal marking 

  • test question – “where will maxi look first of all?”  
    (Siegal & Beattie, 1991) 

  • story comprehension (Lewis et al. 1994) 

• Simplifying the task improves performance but not dramatically – 35%-71% 

substantial developmental effect over preschool years

• < 3.5yrs below chance 
  > 4yrs above chance 

task variables make a difference

• Type of task/question, nature of protagonist/object irrelevant 

• Deceptive motive, active participation and salience of mental state improve performance  

wellman

• Although manipulating several variables improved performance, this was the case across all ages rather than just younger children –not selectively unmasking early competence 

None of the variable manipulations improved performance of 3yos above chance 

universality

(Callaghan et al. 2005) 

• Factors contributing to ToM development 

• Role of social experience in aiding understanding of mental states 

• From interactions with other people 

• Biological maturation enables children to express their understanding of mental states 

• From improvement in executive functioning 

role of experience

Harris (1999) 

• Conversations are crucial for exposing children to other people’s perspectives 

• They provide children with vocabulary needed to discuss and reflect on mental states 

• Children with older siblings show earlier ToM (Perner, Ruffman, & Leekham, 1994; Ruffman, Perner, Naito, Parkin, & Clements,1998) 

• Children whose parents talk about mental states more understand false belief earlier than other children (Dunn et al., 1991; Meins et al 2002; Ruffman, Slade, & Crowe, 2002)  

• Deaf children of hearing parents show a developmental lag on False-Belief taks (Peterson & Siegel, 1995) 

• In contrast, deaf children of signing parents are comparable with hearing children  
  (Peterson & Siegal, 1999) 

theory of mind scale

• Wellman & Liu (2004) 

• Diverse Desires: people can have different desires for the same thing 

• Diverse Beliefs: people can have different beliefs about the same situation 

• Knowledge-access: something can be true, but someone might not know that 

• False Belief: something can be true, but someone might falsely believe something different 

• Hidden Emotion: Someone can feel one way but display a different emotion 

cross cultural differences

Wellman et al (2006) 

• Children in Western countries: 

  • DD>DB>KA>FB>HE 

• Chinese and Iranian children:  

  • DD>KA>DB>FB>HE 

• Thought to be related to differences in cultural values: collectivist vs. individualism  

role of executive functioning

• Children’s failures on ToM tasks may stem not from pure conceptual limitations but rather from problems translating conceptual knowledge into successful action 

• critical role of executive functions in ability to pass ToM tasks 

executive functions

• A set of domain-general cognitive abilities that help us to control and guide our attention and behaviour 

• 1. inhibition

• 2. cognitive flexibility

• 3. working memory

inhibition

• Ignoring distracting information or suppressing unwanted responses 

• Real life 

  • Stop yourself reaching for a bar of chocolate! 

  • Ignoring text message/email alerts when trying to work 

• In the lab 

  • Bear/Dragon task 

  • Stroop paradigm  

  

cognitive flexibility

• Responding to the same thing in different ways depending on the context 

• Real life 

  • Multiple passwords/pin numbers 

  • Talking to different family members 

  • Shopping for different occasions/needs 

•  In the lab 

  • Wisconsin Card Sorting Test 

  • Task-switching paradigm 

biological constraints

• The frontal lobes of the brain are very important for executive functions 

• They take a long time to develop 

• Important developments in Inhibitory control (IC) take place in the first 6 years of life, with marked improvement between age 3 and 6 

• (Diamond & Taylor, 1996) 

role of EF in false belief tasks

• Evidence of strong positive correlation between children’s inhibitory control (e.g. on Bear/Dragon task) and FB performance (Carlson & Moses, 2001; Grosse Wiesmann et al., 2016) 

• Suggests that: development in IC and ToM may be related 

• IC may be a crucial enabling factor for ToM development, possibly affecting both the emergence and expression of mental state knowledge. 

developmental changes in performance on FB tasks

• 3 year old children usually fail FB tasks 

• 4 year old children usually pass FB tasks 

• Traditionally taken as evidence that around this time children ‘acquire’ a theory of mind 

  

• note: above task requires child to make an explicit judgement about another’s mental state. 

 

explicit knowledge

• Knowledge easily accessible to the child 

• Measure via elicited response, e.g. verbal answer to a question 

implicit knowledge

• Knowledge the child is unaware of 

• Measure via spontaneous response, e.g.: 

  • Emotional response (Moll, Kane & McGowan, 2016) 

  • Anticipatory looking (Clements & Perner, 1994) 

  • Violation of expectancy (Onishi & Baillargeon, 2005) 

  

Implicit understanding of FB

Moll et al. (2016) method 

• Investigated children’s facial expressions as indices of their belief understanding 

• Predicted that if 3 yos perceive the conflict between a person’s belief and reality, they will show signs of suspense (e.g. lip biting and brow furrowing) when observing an actor about to act on basis of their false belief  

  

moll et al results

• Found greater instances of expressed tension in the false belief cf. true belief condition 

• Suggests 3 y/os expressed knowledge of another’s false belief and recognised the affective consequences of the false belief 

• In contrast, children’s performance on a classic False Belief task was poor and unrelated to the amount of expressions they displayed while watching the False Belief videos 

• suggests expressions are independent from and emerge prior to explicit knowledge of false beliefs.  

 

(Clements & Perner, 1994) 

Implicit understanding of FB  

• Aim: to get evidence for a period of implicit understanding of FB that precedes the onset of explicit understanding 

• Method: Tested 44 children aged 2y5m – 4y6m on ‘unexpected transfer task’ 

  • Implicit measure  – anticipatory looking 

  • Explicit measure – standard verbal response 

 

anticipatory looking paradigm

• Measure the direction of an infant/child’s first look after an event 

• Participants’ looking behaviour is analysed to determine if they correctly expect/anticipate what will happen next  

• Requires prediction (cf. with VOE, which relies on reactive looking) 

• Clements & Perner (1994) task 

perner results

• 86% children over 2y11m showed looking pattern indicative of FB understanding 

• Only 1 child under 2y11m 

• Dissociation of implicit – explicit understanding of belief 

• 3yr olds looked to correct location even though gave incorrect answer! 

• Large gap between implicit and explicit understanding from 2y11m 

•   Data suggest that children develop an implicit or unconscious understanding of false belief at an earlier age than they develop an explicit or conscious understanding 

  

earlier FB understanding

• Onishi & Baillargeon (2005) 

• Used a totally nonverbal task to test for implicit FB understanding in 15-month-old infants 

• Violation of expectancy method 

• Looking time studies with infants: Violation-of-expectancy method 

• Familiarise infant to an event  

• Present test behaviour that is either: 

  • Consistent  

  • Inconsistent  

  • With the prior event 

• If infant looks longer at inconsistent event taken as evidence that they are surprised 

• Indicates some level of knowledge about what should happen 

looking time study with 15m olds 

• Children can (typically) pass FB test age 4 

• Younger children show non-verbal FB understanding 

• But these tasks may draw on different levels of knowledge (implicit vs. explicit) 

• A Dual Process Model has been proposed to account for this contradiction.. 

dual route model

• Two systems can compute beliefs of others: 

• Fast and efficient system. 

• Slow and cognitively demanding system. 

• (Apperly & Butterfill, 2009)