Date of Award
Doctor of Philosophy
Richard L. Jantz
Rhoda Grell, Fred H. Smith, William M. Bass
The effect of parental age and birth order on dermatoglyphic variation was investigated in a sample of 460 phenotypically normal, Caucasian Americans. The sample consisted of students enrolled in introductory physical anthropology classes at the University of Tennessee, Knoxville, during 1976-77. Twenty finger ridge counts, interdigital ridge counts, interdigital pattern ridge counts, and ridge width in the a-b area were utilized in this study.
In order to remove intercorrelations among dermatoglyphic variables, the dermatoglyphic data were factor analyzed, fingers and palms separately, for each sex. Twelve factors for fingers and 11 for palms were subjected to varimax rotation, and the resulting factor scores for each individual were used in subsequent analyses in lieu of the original dermatoglyphic data. Factor analysis was also used to decorrelate maternal age, paternal age, and birth order.
Factor analysis of dermatoglyphic data indicated that there is an interaction between radial counts on the fourth and fifth fingers, lending support to the idea that they form a distinct functional or biological unit. Factor analysis also indicated that independent mechanisms may be responsible for the development of interdigital ridge counts and interdigital pattern size. Moreover, pattern size seems to function independently on right and left hands, whereas ridge counts for each interdigital area are more closely correlated between hands.
This study revealed a number of significant parental age and birth order effects on dermatoglyphic variation. Effects on ridge count vary considerably between sexes and between fingers and palms, but several areas tend to be affected more than others; these include the interdigital ridge counts, pattern ridge counts in the fourth interdigital area, ulnar counts on digits one and two and on the fourth and fifth digits (acting as a unit). Dermatoglyphic asymmetry tends to be increased on fingers of individuals in high risk categories; intermediate parental ages and intermediate birth orders appear to be optimal in terms of developmental stability of finger ridge counts. A tendency for asymmetry to decrease was observed on male palms with advancing birth order and on female digits with increasing parental ages. Ridge width in the a-b area of the palm was found to be greatest in both males and females of intermediate birth orders.
Oliveira, Letitia Lowe, "Dermatoglyphics of University of Tennessee Students: Effects of Parental Age and Birth Order. " PhD diss., University of Tennessee, 1978.