Criticisms of Piaget

There are many who criticize Piaget, one is Margaret Donaldson, she was a pupil of Piaget's who challenged his theories in a her 1978 book, Children's Minds.

pre-school children are not nearly so limited in their ability to 'decentre', or appreciate someone else's point of view, as Piaget has for many years maintained.
(Donaldson, 1978: 30-31).

The evidence she gives to support this is that the experiments Piaget uses are not explained properly to younger children, two of the the same experiments were carried out by Martin Huges and explained properly to a child; they were able to do it.

In  another  study,  Hughes  used  a  simplified  version  of the
mountains task and found that it was possible, by taking great care
over the way  in which the problem was introduced, to get a high
proportion · of correct responses  from  pre-school children.  So  this
lends  further  support  to  the  view  that  Piaget's  subjects  did  not
understand.                                                                                                      (Donaldson, 1978: 23).

Donaldson also refers to the ‘mountains experiment’ as being to abstract, she also states that a person preforming these experiments is accustomed to abstract and formal  modes of thought. These abstract experiments seem bewildering and senseless to a child.

Donaldson also shows evidence that Piagets idea that a child belives an object ceases to exsist when it is coverd; Tom  Bower  and  Jennifer Wishart, report that in these circumstances  children quickly reach out in the appropriate direction to find  their  toy  again:  Thus  Piaget'.  claims  about  egocentrism  are once again challenged. They are yet to develop  a  full appreciation of spatial relations  such as on,  in,  in front  of,  and  behind. * They  do  not derive  from  the complete lack of a notion of a world of 'other things'.

Another experiment was done by David Lloyd in which a talking toy panda asked for help. He found that, though the children would try to help the
panda, they were not so ready to signal when they themselves needed help. They were not given to indicating that a message which they had received was inadequate. 

Therfore, the evidence shows that its not so black and white; pre-school children are not nearly so limited in their ability to 'decentre', or appreciate someone else's point of view.