Abstract
Background: Models of cognition propose a hierarchical structure for human cognitive processes, in which the sequences of human action are organized into parts or subunits of analysis that can be grouped into progressively more complex, inclusive higher-order functions. This organizational structure from partial to whole may be reflected in the neural representations that underlie human behaviour, and in its genetic underpinnings. The objective of the present study was to explore a putative hierarchical organization of the genetic influences underlying cognitive domains. Method: Thirty four studies of the heritability of cognition on population-based samples were reviewed, which included measures of intelligence, verbal and performance abilities, memory, working memory and processing speed. Results: Specific cognitive domains showed diverse proportions of genetic underpinnings such that higher-order cognitive functions present high heritability estimates, whereas lower-order functions respond to small/moderate heritability estimates. Conclusions: Based on current understanding of the developmental processes of the neurobiological substrates of human cognition, the genetic contributions to cognitive abilities seem to be organized in line with the ontogenic maturation of the brain. We discuss the large genetic control of the combinatory capacity of basic cognitive functions, and its interaction with environmental influences.
