Innovation and the evolution of human behavior. Brain evolution, innovation, and endocranial variations in fossil hominids

Abstract

The archaeological record provides compelling evidence that human artifacts became more and more sophisticated over time. The ability to innovate is therefore assumed to be a trait already present in our ancestors. Prehistoric artifacts give us some indirect insight into the cognitive capacities of their respective makers. Additionally, variations in endocranial morphology explain changes in the spatial organization of the neural mass. Neuropsychological research has significantly enhanced our understanding of how and where mental abilities are realized in our contemporary brains. Increasingly sensitive brain imaging techniques and adept experimental designs support the development and verification of biologically plausible models of cognitive processing for complex behavior such as creative thinking. In addition, primatology studies elucidate similarities and differences in the mental capacities between us and our closest living relatives. In combination, findings from the archaeological and the fossil record and our understanding of the capacities of present-day human and non-human primates allow us to detect and interpret gradual evolutionary changes in the human brain, which were potentially crucial for the development of specific mental processes. With regards to capacities associated with creativity, modifications within frontal, parietal, and cerebellar areas, as well as changes in the relationships between these areas and in hemispheric asymmetry are of particular interest. This article presents recent findings of this interdisciplinary approach and also draws attention to methodological limits and the many uncertainties that currently remain. Additionally, the possible link of innovative thought with changes in the human life-history pattern is discussed, namely the emergence of rather distinct stages of childhood and adolescence, which may play a major role for the surge of cultural transmission in our species.