I.P.A.T. is the study of ridged skin patterns (also known as dermatoglyphs) which can be found on fingers, palms, toes and soles. These patterns are formed from the external ectoderm and usually occur during the fetal development stage, 13 to 19 weeks after fertilization. Through research, geneticists have proven that dermatoglyph formations are controlled by chromosomes, and the patterns are influenced by polygenetic inheritance. These genes do not exhibit dominance, and they are very resistant to acquired changes from the environment. Using their morphologies, the patterns can be classified into two categories, namely “ridges” and “furrows”. During the seventh week of pregnancy, vertical thumb creases (thenar contours) begins to appear on the palm of the embryo. Two weeks later, remote and proximal horizontal creases (hypothenar contours) begin to form.
Hirsch and Schweicher discovered that prior to the formation of dermatoglyphs, the dermal nerves and blood vessels are arranged in an orderly fashion. This led them to believe that the nervous and vascular systems determine the formation of dermatoglyphs. Consequently, they also established the correlation between the dermatoglyphic patterns and one’s personalities.
From the anatomical point of view, the human hands dominate all other organs in terms of relative importance. This is why the brain dedicates the majority of approximately two hundred million nerve endings to the hands. In other words, the hands are sources of physiological and psychological information waiting to be tapped, hence the increasing importance in the field of I.P.A.T..