This work was undertaken to determine the genesis and role of creativity (Cr) in the formation of mental qualities that gave Homo sapiens (HS) the evolutionary advantages in intra- and interspecific competition during the period of the intraspecific bifurcation of hominids on the border of the Middle and Upper Paleolithic. Creativity allowed HS to design the adaptive forms of purposeful behavior corresponding to the conditions and the degree of uncertainty, and create stable mental constructs, in the absence of perceptual sources, that do not require reactive behavior. Visualization of a target image, which originally had an applied and instructional value in the process of semantic filling, was transformed into a symbol, which, getting the qualities of the perceptual source, loses its connection to the primary value and initiates the creation of qualitatively new needs for hominids: bilateral (direct and inverse) relations in the system "subject-symbol." The ability to produce the prognostic hypothesis with expansion of the operating range of the HS mind allowed the ability to search and change the tactics of an adaptive behavior, which gave the results: improvements in quality of life and an increase in life expectancy (genetically fixed); domination in intra- and interspecific competition; the emergence of new operating systems of the psyche, including the emergence and development of symbolic thought. As a criterion of creativity, with the potential ability for quantitative measurement, we propose the value of deviation of creative oscillations ("proposal" of a creative individual) from the boundaries between stereotypes: for the cognition sphere, a deviation from the border between recognizable and unrecognizable; for the social sphere, between acceptable and unacceptable.