Baillargeon and Violation of Expectation

• violation of expectation

  refers to situations or events which contradict what an infant thinks will happen, based on their understanding of the world
• Baillargeon procedure

  • 32 3.5 month old infants recruited using the birth announcements in local papers
  • after habituation, they watched a short or tall carrot slide along a track in both possible and impossible event
  • they were seated on parents' laps and parents were asked not to interact and to close their eyes
  • two researchers, blind to the conditions, recorded how long infants spent looking at each test event
• Baillargeon's findings

  • the infants looked reliably longer at the tall than at the short carrot even
  • inter-rater reliability was 0.91
  • suggests that they represented the existence, height and trajectory of each carrot behind the screen and expected the tall carrot to appear in the screen window and were surprised that it did not
• Baillargeon's theory of physical reasoning

  • we are born hard-wired with both a basic understanding of the physical world and the ability to learn more details easily
  • this becomes more sophisticated as we learn from experience
  • in the first dew weeks of life, infants begin to identify each event category response to one way in which objects interact
• strong methodology

  participants were drawn from birth announcements in the local newspaper

  • more representative than others because you get a wider mix of people
  • only geographically looking in one area

  during the tasks, children sat on their parents' laps and they were instructed to keep their eyes closed and not interact

  • can't influence the child's behaviour
  • reduces the effect of demand characteristics, increasing internal validity

  two blinded observers watched and recorded the length of time infants spent gazing at events

  • reduces observer bias
  • inter rater reliability
• conclusions are flawed - inferences

  • does babies looking mean that they are surprised
  • affects internal validity
  • no empirical evidence
  • 22/32 of the babies were excluded (e.g. fell asleep), overestimates
• explanatory power/evidence

  • while infants have object permanence by 3-4 months, they fail to be surprised at changes in clout until 11.5 months
  • therefore, the evidence suggests that infants are born with some ability to understand and represent objects, but this becomes more sophisticates through experience as Baillargeon argued