Reed T, Norton J A, Christian J C
Hum Hered. 1978;28(5):351-60. doi: 10.1159/000152977.
Factor analysis was employed using the ulnar ridge count, radial ridge count, ridge count (the larger of the radial or ulnar count as generally used for calculating total ridge count), and pattern type for each finger in 720 twins. Pattern type and ulnar count displayed parallel factor loadings while loadings for radial and ridge count also paralleled each other. This relationship did not hold for the index finger, indicating the importance of pattern direction and greater pattern diversity for this digit. Total ridge count was most closely associated with a factor of ring and little finger radial and ridge count and only secondarily with an index finger factor. When radial and ulnar counts were deleted to make comparisons with earlier studies, the result was factors having groupings of variables identical with previous reports. It appears that factor analysis results in consistent extraction of identical or very similar factors from different populations, and the use of radial and ulnar counts adds more information than when only the larger of the two counts is considered.
对720对双胞胎的每根手指的尺侧嵴计数、桡侧嵴计数、嵴计数（通常用于计算总嵴计数的桡侧或尺侧计数中的较大值）和花纹类型进行因子分析。花纹类型和尺侧计数显示出平行的因子载荷，而桡侧和嵴计数的载荷也相互平行。这种关系在食指上不成立，表明花纹方向和该手指更大的花纹多样性的重要性。总嵴计数与无名指和小指的桡侧和嵴计数因子最密切相关，其次才与食指因子相关。当删除桡侧和尺侧计数以与早期研究进行比较时，结果是得到了与先前报告中变量分组相同的因子。似乎因子分析能够从不同人群中一致地提取相同或非常相似的因子，并且使用桡侧和尺侧计数比仅考虑两者中的较大值时能增加更多信息。
