Finger misrepresentation and dyscalculia in an ecological context: toward an ecological (cultural) evolutionary neuro-psychiatry.

A new model posits the existence of a general link between ecological (cultural) factors and post-natally evolving cognitive functions and in particular the emergence of such functions in specific clusters. Such "ecological syndromes" are characteristic of a significant portion of a cultural group and analogous to syndromes found with certain brain lesions without implying them. Presently a specific link is noted between known low skills in arithmetic and as tested here, quantitatively inaccurate pictorial (and implied mental) representation of fingers in 78% of New Guineans and 70% of Indonesians living in remote areas, while only 16% of Western European regular school children (ages 7 to 10 yr.) misrepresented the fingers in drawing a person. Previously a link between low literacy skills and inaccurate spatial relations in representing the pattern of the face was found for diverse time periods and cultural groups.