Fink Bernhard, Thanzami Vanlal, Seydel Hanna, Manning John T
Department of Sociobiology/Anthropology, University of Göttingen, Göttingen, D-37073, Germany.
Am J Hum Biol. 2006 Nov-Dec;18(6):776-82. doi: 10.1002/ajhb.20549.
The ratio of the length of the second and fourth digits (2D:4D), a putative proxy of prenatal testosterone (PT), is correlated with measures of physical fitness. The relationship between the organizing effect of PT on physical fitness is likely to arise as a response to intrasexual male competition for females. Physical strength is also likely to be important in intrasexual conflict, but nothing is known concerning the relationship between 2D:4D and strength. The strength of an individual is strongly influenced by body size, and 2D:4D is strongly dependent on ethnicity. We present evidence that strength, as measured from hand-grip strength, is related to 2D:4D in samples from two ethnic groups (52 Caucasian men from Germany, and 88 Oriental Mizos men from northeast India) which differed markedly in size. We found that 1) the German men were heavier and stronger, but had higher 2D:4D (lower PT) than the Mizos men; 2) a median split for grip strength into low (LGS) and high (HGS) groups showed that for right-hand 2D:4D (but not left-hand 2D:4D), the LGS men had higher 2D:4D than the HGS men; and 3) the relationships between right 2D:4D and grip strength were independent of ethnicity, age, height, and weight. Measures of grip strength correlate strongly with strength in other muscle groups, so we conclude that PT may have an early organizing effect on strength in men, and this is likely to be widespread in human groups.
第二和第四指长度之比（2D:4D）被认为是产前睾酮（PT）的一个代理指标，它与身体素质指标相关。PT对身体素质的组织效应之间的关系可能是作为男性为争夺女性而进行的同性内部竞争的一种反应而产生的。体力在同性内部冲突中也可能很重要，但关于2D:4D与力量之间的关系却一无所知。个体的力量受体型的强烈影响，而2D:4D很大程度上取决于种族。我们提供的证据表明，在来自两个体型差异显著的种族群体（52名德国白人男性和88名印度东北部的米佐族东方男性）的样本中，从握力测量得出的力量与2D:4D有关。我们发现：1）德国男性更重更强壮，但他们的2D:4D（较低的PT）比米佐族男性更高；2）将握力按中位数分为低握力（LGS）组和高握力（HGS）组，结果显示，对于右手2D:4D（而非左手2D:4D），LGS组男性的2D:4D高于HGS组男性；3）右手2D:4D与握力之间的关系不受种族、年龄、身高和体重的影响。握力测量与其他肌肉群的力量密切相关，所以我们得出结论，PT可能对男性的力量有早期组织效应，而且这种效应可能在人类群体中普遍存在。
