Matheny A P
Percept Mot Skills. 1979 Dec;49(3):751-5. doi: 10.2466/pms.1979.49.3.751.
Data from a longitudinal study of twin children and siblings, 155 girls and 134 boys (aged 4 to 9 yr.), on a torque test confirmed that during this age period manually produced circling patterns change from clockwise to counterclockwise orientation. A genetic influence is suggested.
一项针对双胞胎儿童和兄弟姐妹（155名女孩和134名男孩，年龄在4至9岁之间）的纵向研究数据，通过一项扭矩测试证实，在这个年龄段，手动产生的圆周模式从顺时针方向转变为逆时针方向。研究表明存在遗传影响。
