Sex Differences in the Intraindividual Diversity of Finger Dermatoglyphics: Pattern Types and Ridge Counts

The intraindividual diversity and the asymmetry of finger der- matoglyphics, pattern types and ridge counts were comparatively studied in 872 males and 462 females. Observations carried out on these samples point out a tendency to formation of a definite pattern type, with similar ridge counts on all the ten fingers of an individual. Some factors counteracting this tendency and conducive to intraindividual diversity are enumerated.For measurement of intraindividual diversity of pattern types, the use of the Shannon measure of diversity is here proposed. In males, according to our results, this index has a greater mean value and presents more frequently maximal values than in females. Also greater in males is the intraindividual diversity of ridge counts, represented by the index S√5 and intralateral diversity, represented by the indices S2R, S2L IIDR and IIDL. The sex dif­ferences in intraindividual diversity were found to be better expressed on the right hand, owing to a gteater differentiation of the right fingers in males.The ambidirectional asymmetry in ridge counts has near values in both sexes. A tendency to a better expressed directional asymmetry was observed in males whereas the fluctuating asymmetry tends to be greater in females