Focus of chapter is on three aspects of cognitive development:
- Infant’s understanding of objects
- The way infants respond in a special way to people
- The ability of infants to use models as representations of the world
- Cognitive processes aren’t observed directly, but have to be inferred from behaviour
- Unambiguous evidence is rarely produced
- Interactionist and nativist positions provide different interpretations of the same results
Piaget – in the early months infants have no concept of object permanence – takes until 8-9 months old until they look for an object that has disappeared. Evidence from an experiment where an object is hidden under a cloth. Conclusion based on studies of just a few infants, but other researchers have confirmed robustness of the result. Butterworth – one of the major achievements in the first months and worthy of study because of this. (Interactionist interpretation.)
Expectation as a clue to understanding
Another interpretation of the same result is that although the infant understood what was happening, they couldn’t physically co-ordinate their response before 8-9 months. Bower investigated with a train stopping behind a screen and watched where a child’s gaze went. Findings appear to contradict Piaget as children as young as 2 months would anticipate the train’s reappearance, but a modified version where the train is stopped before the screen showed that the child’s gaze continued to track – therefore gaze not an indicator of understanding of object permanence.
Violation of expectations
Habituation – less attention is paid to familiar events. Violation of expectations – relies on the idea that more time is spent looking at events that are ‘impossible’.
Baillargeon et al – habituation of 5 m.o. infants to a 180 degree rotation of a drawbridge. Wooden block placed to impede rotation at 120 degrees. Condition 1 – left there, drawbridge stops; condition 2, block discretely removed when drawbridge vertical, so rotation carries on to 180 degrees. Finding was that infants paid more attention to the ‘impossible’ 180 degree event than the ‘possible’ 120 degree event, despite habituation. Possible interpretations were:
(i) infants were interested in the drawbridge apparently going through a solid object => implies they ‘know’ there is a hidden block (i.e. demonstrates object permanence younger than Piaget argues.)
(ii) infants spent longer looking at 180 degree rotation because it takes longer? Trials re-run to account for this possible confounding variable – same result.
Conclusion – (i) they believed the block continued to exist even when obscured and (ii) they understood the presence of an invisible object was an obstacle to the progress of the drawbridge.
Another variant – toy car, track blocked / not blocked by a hidden obstacle behind a screen. 6-8 m.o. behave in same way as adults – surprised if the block is removed from the track when behind the screen and its motion continues. Findings replicated on 3.5 m.o. children by Baillargeon…