A study of passive movements and an analysis of the prehensile patterns of movement of the anthropoid ape hand was carried out in two young chimpanzees and one young orangutan, all approximately two years old at the time of study. The passive movements compare closely with those of a human child except in respect of the wrist and metacarpophalangeal joints of the fingers; in the case of the former joint, while flexion was very full, extension was limited. Passive movement of the metacarpo-phalangeal joints was also very full, movement being limited only by contact of the fingers with the palm. A “double-locking” mechanism of the 2–5th digits taking place at the metacarpo-phalangeal joints is described. The anatomical basis of these movements and the “double-locking” mechanism is discussed. Active movements were studied in terms of the prehensile patterns of the human hand (Napier, 1956) and it is shown that, while there is evidence of a functional duality of prehension in the hands of young anthropoid apes, the execution of the two grips differs profoundly from that of Man; the difference is discussed in terms of the disproportion in the length of the thumb and fingers in apes. It is suggested that the “double-locking” mechanism of the fingers compensates in some measure for the ineffectiveness of the thumb in prehension.

Studies of the hands of living primates

Dermatoglyphic stigmata in mongoloid imbeciles

The breadths of epidermal ridges on the finger tips and palms: A study of variation

Dermatoglyphic a-b ridge count as a possible marker for developmental disturbance in schizophrenia: replication in two samples

Research in dermatoglyphics having direct interest and application to anthropology has continued to grow since the turn of the century. Anthropological dermatoglyphics can offer important perspectives in viewing the nature and significance of human variation. Several forefronts of ongoing research are reviewed. First, methodology continues to improve definition and classification of variables. A second line of inquiry deals with hereditary aspects. Inheritance models, both monogenic and polygenic, have been proposed. Single locus systems seem to have limited application, as in the transmission of triradial excess or deficiency illustrated by the missing c triradius. Polygenic inheritance has been demonstrated in quantitative phenotypic expressions exemplified by the total finger ridge-count. Exciting recent research employing the “field concept” has discovered a small number of developmental factors which correspond well with earlier findings on volar pad development and dermatoglyphic features. Maternal and other environmental effects have been shown to operate on dermatoglyphic expression. Human population studies using dermatoglyphics began with early racial descriptions and currently utilize multivariate procedures for detecting evolutionary processes. Congruence testing between dermatoglyphics and other biological distance measures is also an active endeavor. In this connection, dermatoglyphic variable selection has become important in recognizing that different variables might well be useful in micro- and macroevolutionary situations. Finally, dermatoglyphic analysis has. been applied to primate studies. Although this area has not kept pace with human studies, primate work has been crucial for the important matters of taxonomic assessment and functional dermatoglyphics.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ajpa.1330230509

Harriet H. Keith

Papers

Revised methods of interpreting and formulating palmar dermatoglyphics

Racial differences in the papillary lines of the palm

Study of error in interpretation and formulation of palmar dermatoglyphics