We looked for these features in a socioemotional transition expected to occur at 18-20 months. Infants were given frustrating toys while their mothers sat nearby without helping, on 12 monthly visits before, during, and after the hypothesized shift. State space grids representing patterns of behavioral durations were constructed for each episode and compared over age. However, an unpredicted linear decrease over age in real-time variability, and discrepancies between tasks, indicated differing developmental profiles as a function of task and measurement factors. Self-Organizing Brains Don't Develop Gradually.
Some dynamic systems approaches posit discontinuous changes, even universal stages, in development.
Conversely, Thelen and colleagues see development as gradual because it relies on real-time interactions among many components. Yet their new model hinges on one parameter, neural cooperativity, that should change discontinuously because it engenders new skills that catalyze neural connectivity. After decades of theoretical fragmentation and insularity, a converging explanatory framework based on general scientific principles is an important goal for developmental psychology. Dynamic systems approaches may provide such a framework, using principles of self-organization to explain how novel forms emerge without predetermination and become increasingly complex with development. New trends in traditional theoretical families emphasize systemic, emergent processes, and these can now be explicated with principles of self-organization that apply to all natural systems.