Piaget – Preoperational stage

1. Piaget – Preoperational stage

2. Object permanence Infants who have yet to gain a firm understanding of object permanence fail to track the motion of a toy when it enters a tunnel

3. Class inclusion tasks • 10 beads: 7 black, 3 white Are there more black beads or white beads? Black... Are there more black beads or beads? Preschoolers say black beads

4. Class inclusion According to Piaget, because they center on only one level of categorization, either on the two subclasses or on the united common class Cannot consider the two levels simultaneously

5. Egocentrism Early understanding of others’ mental states Chandler created a treasure hunt game, where a treasure was hidden in a container by a doll who left a trail of footprints to the treasure the child was asked to make it difficult for people to find the treasure

6. Egocentrism – Early understanding of others’ mental states • most 2.5 and 3 year olds erased the footprints in order to conceal the route to the treasure • deception is a process of instilling a false belief in the other • early use of deception indicates that they can reason about other people’s beliefs

7. Three mountains • Preschool children shown this diorama of three mountains with a distinctive landmark on each mountain were unable to say how the scene might look from perspectives other than the one they had at the moment (from Piaget & Inhelder, 1956)

8. Hide the doll from the policeman! A B Toy Policeman D C Child (real!)

9. Hide the doll from both policemen! Toy policeman A B Toy Policeman D C Child (real!)

10. And the findings? • “When 30 children between the ages of 3.5 and 5 years were given this [the 2nd] task, 90% of their responses were correct. And even the 10 youngest children, whose average age was only 3y 9m, achieved a success rate of 88%” • Donaldson (1978); p22)

11. Modified 3-mountain perspective taking task Children were presented with a more familiar scene than the three mountains-- a farm scene that has a building, a lake with with a boat in it, and a horse and a cow were asked to describe how Grover’s view of the scene looked like as he drove around the farm 3 yrs-- 80% correct 4 yrs-- 93% correct vs. 42% correct for 3 year olds and 67% correct for the three mountains task what does Grover see?

12. Borke’s (1975) experiment • The character in the car is from Sesame Street. He drives round the landscape. From time to time he stops and takes a look at the view. What’s the view like? • Children as young as 3 years performed well on this task although the same child had performed poorly on ‘3 mountains’ • So – familiarity is important! • What does it say about egocentrism and age?

13. Conservation: a classic • But there are several kinds: • Amount • Number • Length • Weight • (and that’s not the complete list)

14. Conservation of amount • The procedure Piaget used to test conservation of amount. First, present two beakers of equal size with equal amounts of liquid. Then present a taller, thinner beaker and pour contents of one of the other beakers into it. Finally ask “Which beaker has the more liquid or do they both have the same amount? • How did the little girl do?