In the previous chapter we found that markets contribute to cognitive complexity largely through their influence on the kinds of work people do and their relief of poverty. On the other hand, firms often did not systematically reward complex cognition (often they could not afford to train for it) and they have not, until recently, banded together to give political support for a level of public education appropriate to its influence on the economy. In this chapter I continue the examination of market effects on cognitive complexity by turning to the influence of environmental stimulation and stress on cognition.

The market, as a source of both challenge and stress, by its very nature demands difficult cognitive responses. As a self-regulating system the market is not equipped to regulate or inhibit over stimulation. It has no terminal facilities for stimuli. There is no systemic brake or inhibition (except for individual choice) that might tailor demands to the variety of capacities among market participants. The thesis of this chapter is that market effects on cognition follow a curvilinear pattern whereby they first increase cognitive complexity by their challenges, innovations, and propensities for rapid change, and then often overload the capacities of their participants by their demands for complex cognitions. I first present evidence of curvilinearity in laboratory, field, and historical studies, then turn to evidence of market complexities leading to overload. After exploring some social consequences of this pattern, we will examine models where environmental complexities occur either simultaneously or in sequence, concluding with an examination of adaptive responses in these different circumstances.