Experiments 1 and 2 investigated 3- and 4-year-olds' understanding of
the intended nature of pretend behaviors by testing their ability to d
istinguish between involuntary behaviors and the same behaviors emitte
d intentionally through acts of pretend. Four-year-olds' high rate of
passing showed that (1) they understood intention as a mental cause of
action and (2) they construed pretend behaviors mentalistically. Expe
riment 3 used the same contrastive procedure to examine Lillard's cont
ention that 4-year-olds do not understand the knowledge conditions and
hence the mental representational component of pretend actions. Where
as nearly all of the 5-year-olds understood that an agent who did not
know of a specific animal could not be pretending to be that animal, 4
-year-olds systematically associated ignorance with pretend. On the ba
sis of the combined findings of the present experiments, and other res
earch showing a mentalistic understanding of pretense by the age of 3
or 4, it was concluded that the specific reasoning requirements of Lil
lard's tasks resulted in an underestimation of children's appreciation
of the mental features of pretend.