We studied cognitive inhibitory processes and verbal regulation of behavior of individuals with different levels of education (including adult illiterates) in Brazil (N = 136) and in Estonia (N = 560) with person-oriented methods of data analysis. Our aim was to discover whether dominant type of word meaning structure (WMS) can define the "Great Divide", the single breaking point that universally defines certain direction of subsequent to it cultural evolution. We found that both cognitive inhibition of irrelevant for the task at hand information or actions as well as correct activation of relevant information or actions is significantly more common in individuals who rely predominantly on logical concepts in their thinking. The higher level of education was also associated with more efficient cognitive inhibition and activation. The patterns of test performance also suggest that there can be a qualitative difference in the efficiency of cognitive inhibition-activation processes between everyday conceptual and logical conceptual thinkers. The former group of individuals may achieve much higher performance levels than any individual in the former group. We also discuss cognitive similarities and differences between adults with low or no formal education on the one hand and children and educated adults with brain damage on the other. The results are in agreement with the theory of unilineal hierarchic cultural evolution. Individual psychic development and cultural evolution can be both understood in terms of the WMS development.
Keywords: Great Divide; cognitive inhibition; illiteracy; level of education; unilineal evolution; verbal regulation of behavior; word meaning structure.