Piaget's stages of cognitive development

• 0-2
• Discovering relationship between themselves and the environment
• Cognitive milestone: Object permanence (understanding that objects can exist beyond the child's sight)
• Imitation
• development of gross motor skills (pushing & pulling)
• Mastery play
• Develops perseverative search (looking for an object where it usually is & not where it was last)
• Develops deferred imitation (ability to imitate behaviour that was seen previously) 

• 2-7
• Egocentric (3 mountains task)
• Semilogical
• Seriation (ability to arrange objects in order based on a single feature)
• Syncretic thought (ability to take account of 2 or more aspects of a situation at a time)
• Language becomes more mature
• Memory and imagination developed 
• engage in make-believe
• Ruled by intuition

• 7-11
• Decentering (open to others perspectives and views)
• Cognitive operations combined
• Cognitive operations related to maths and logic
• Seriation (putting things in logical order)
• Transitivity (see logical relationship between objects)
• Conservation; quantity of liquid 7-8, weight 8-10, volume 11-12
• Research: Counters task, waterbeaker task
• Masters concept of reversibility
• No abstract or hypothetical concepts

• 11/12 upwards
• Deductive and inductive
• Systematic planning and organisation
• Ability to think logically about events or abstract ideas
• Able to consider hypothetical ethical issues
• Not tied to perceptions &/or concrete reality, can think beyond the limitations of immediate reality
• Able to generate hypothesis and test them

• 1st comprehensive account of cog dev in kids & most deveoped theory
• Generated extensive research
• Practical applications: education, child-minding, childrens toys
• Piaget maintained that only the sequence of the stages were important, the age ranges of the stages were only a vague indicator
• Piaget's concept still used
• Stages too rigid, not room for ind diff
• neglects factors like memory span, motivation, impusiveness & practise, which could explain developmental differences
• Kid's faliure on cog tasks may be due to methodological issue on Piaget's part (as said by Danner & Day)

Bower'82 found some aspects of object permanence are present much earlier than at 9 months when Piaget claimed. 

He found children at 3-4 months showed suprise when an object previously seen disappeared. 

This means that Piaget's finding lack internal validity, as his results may have been affected by extraneous variable as a result of methodological factors rather than the ability of the children.

Piaget's 3 mountain task found that kids under 7 cannot see from others perspectives (egocentric)

Wheldall found children failed conservation tasks because the question was too complicated.

He created a non-verbal task instead and found 50% of Pre-operational kids completed the 1st task successfully compared to 28% completeing the traditional procedure

This demonstrates that Piaget's procedure lacks internal validity and is affected by methodological issues

Hughes'75 produced counter argument to Piaget's work and found 90% were able to solve a variation of the 3 mountains task much earlier than Piaget said. 

The role of experience of motivation was key to them being able to solve the task as it had more mundane realism. (more relatible so they were able to decenter)

Cowan attempted to coach children on conservation and failed.

This agrees with Piaget's theory as he thought biological maturation, not environment was responsible for cog dev

Link to nature/nurture debate-nurturing/teaching did not enable the child to develop faster. (IDA)

It is not clear to what extent all adults actually ever do reach the formal operations stage.

Wason & Shapiro used an abstract complex card task and found only 5-10% of university students could solve it. 

When a concrete version of the task was used (w/cars) 62% were successful. It had more mundane realism meaning it was more appropriate for them.

Pendulum problem-what determines the frequency of swings of a pendulum? -Length of string. Only formal operations kids answered correctly. This shows that abstract ideas can only be fully understood during this stage.