Howard Gardner no longer believes in Piaget's theory of how the mind develops. His specific points of disagreement are these.
Piaget believed in general stages of development that cut across contents (Space, time, number); I now believe that each area of content has its own rules and operations and I am dubious about the existence of general stages and structures.
Piaget believed that intelligence was a single general capacity that developed pretty much in the same way across individuals: I now believe that humans posses a number of relatively independent intelligences and these can function and interact in idiosyncratic ways,
Piaget was not interested in individual differences; he studied the 'epistemic subject.' Most of my work has focused on individual differences, with particular attention to those with special talents or deficits, and unusual profiles of abilities and disabilities.
Piaget assumed that the newborn had a few basic biological capacities — like sucking and looking — and two major processes of acquiring knowledge, that he called assimilation and accommodation. Nowadays, with many others, I assume that human beings possess considerable innate or easily elicited cognitive capacities, and that Piaget way underestimated the power of this inborn cognitive architecture.
Piaget downplayed the importance of historical and cultural factors — cognitive development consisted of the growing child experimenting largely on his own with the physical (and, minimally, the social ) world. I see development as permeated from the first by contingent forces pervading the time and place of origin.
Finally, Piaget saw language and other symbols systems (graphic, musical, bodily etc) as manifestations, almost epiphenomena, of a single cognitive motor; I see each of these systems as having its own origins and being heavily colored by the particular uses to which a systems is put in one's own culture and one's own time.
The key concepts creating differences between Gardner and Piaget seem to be:
assimilation/accommodation,
stages,
general capacity (epistemic subject),
individual difference/commonalities (decalague),
innate abilities at birth,
social and cultural versus isolated child (social factor)
language.
