The assumption that children’s imagery abilities become more and more independent from overt
motor activities is in line with Piaget and Inhelder’s (1948/1956; see also Piaget, 1936/1952) theory
insofar as these authors emphasized the emergence of cognitive abilities out of sensorimotor abilities.
However, according to their theory, differences in the importance of sensorimotor feedback would be
expected much earlier, at the transition from the sensorimotor stage to the preoperational stage. The
current results, and more specifically the visualization of the effect sizes of the factor diameter in
Fig. 4, show that the developmental pattern is not as stepwise as the use of statistical significance levels
might purport. The pattern rather suggests a continuously increasing independence from sensorimotor
feedback with age. This interpretation is in line with Thelen (2008), who proposed that there is
a tight coupling among action, perception, and cognition early in life—a coupling that remains well
into adulthood but becomes more flexible and adaptive during the course of development.