While the grand sweep view of development may
seem to show the existence of universally occurring stages, more detailed
observations at shorter time scales and in different domains will show that
new behavior emerges from the continuity of interacting variables over time.
Minute changes in seemingly unrelated domains may lead to major changes
in the self-organizing system and can lead to relevant individual differences.
Summarizing their argument to see cognition as a dynamic system, Smith and
Thelen (2003) conclude:
In human development, every neural event, every reach, every smile, and
every social encounter sets the stage for the next and the real-time causal
force behind change. If this is so, then we will gain a deeper
understanding of development by studying multicausality, nested
timescales and self-organization. (p. 347)