ToM

• Theory of Mind (ToM)


  Our guesses or "theories" about other people's minds
• False belief


  When other people hold a belief about the state of the world that does not match reality
• True belief


  When other people hold a belief about the state of the world that matches reality
• Children develop true belief ToM before they develop false belief ToM
• Initial studies showed ToM develops after 4 years of age, but this view is now changing
• Orders of ToM


  • What do you think?
  • What do you think that I think?
  • What do you think that I think that you think?
  • What do you think that I think that you think that I think?
• Most people can do up to 4th order ToM. After that, it becomes cognitively very challenging.
• Implicit vs explicit measurement tools

  • Age-appropriateness
  • Executive function requirements (e.g., memory, meta-thinking)
• False-belief tasks


  • Smarties task
  • Sally – Anne task
• Violation of expectation


  • Designed as a non-verbal measure of ToM
  • Used primarily with infants
  • Based on the idea that infants who have ToM will form predictions about how an agent will act next
• Anticipatory looking


  • Also designed as a non-verbal measure of ToM
  • Also used primarily with infants
  • Based on the idea that infants who have ToM will divert their eye gaze to where they predict the agent will go before the agent happens
• Interaction behaviour


  • Used with children over 2 years old
  • Children are active rather than passive observers of others' interactions
  • Adaptation of the Sally – Anne task with the child being involved in the interaction
• Precursors of ToM


  • Self – other distinction
  • The goals of other people's actions
  • The intentions underlying other people's actions (even when action goals are not met)
• Self – other distinction


  The ability to represent self as one sort of object among, but distinct from, all other objects
• Development of self – other distinction


  1. 24-hour-old newborns: Notice similarity between own body and others' body

  2. 3 – 5 months: Identify self-initiated actions using contingencies

  3. 9 months: Social engagement only with others, not with self

  4. 12 – 15 months: Sharing attention with others

  5. 15 – 24 months: Prosocial engagement
• Goal understanding


  As of 6 months, infants predict the outcome of others' actions
• Intention understanding


  As of 9 – 10 months, infants can identify intentions underlying others' actions – even when action goals are not met
• All necessary precursors of ToM are in place (at least in rudimentary form) by age 2
• Early studies showed a distinct shift in ToM abilities at 4 years of age
• Meta-analysis of 1469 infants: Infants are 1.76 times more likely to respond correctly to implicit ToM tasks than to respond incorrectly
• Meta-analysis of 178 studies: Regardless of how the ToM questions are asked, children under 3 years of age (36 months) don't respond correctly above chance
• Children of all ages showed improved performance with implicit tasks
• No evidence for ToM development before age 3 – earlier than initial findings, still!
• Two "revolutions": Major changes at 9 months and 4 years


  • Basic ToM at 9 months: perception – goal psychology
  • Fully-fledged ToM at 4 years: belief – desire psychology
• Certain social-cognitive skills must precede ToM development: self – other distinction, goal and intention understanding
• At what age ToM develops is still debated: Precursors are in place much younger than 4, but is that still the same ToM?
• Most recent reviews show a continuous development of ToM with 'jumps' at 9 months and 4 years
• Note on suggested readings: Prioritise reviews and meta-analyses to understand counter-arguments. Read individual studies to understand the methods!