一次无力的握手所透露的信息或许比这个男人告诉你的还要多。根据一项新的研究，强健的握力是遗传健康的一项指标。这一发现将握力与侵略性行为和性行为联系起来，甚至使人们有机会了解欺凌弱小者的那些人的心理状态。
握手的力度（HGS）是一种遗传特征；一个人的握力大约有65%是由遗传因素决定的，而剩下的35%则取决于后天训练和发育因素，例如营养等。之前的研究将HGS与不同的生理条件指标联系在一起，其中包括骨骼密度和寿命。美国纽约州奥尔巴尼大学的进化心理学家Gordon Gallup指出：“这是一个关于健康和活力的普遍适用的度量标准。”
为了搞清HGS是否也能反映性别与社会行为，Gallup和他的同事从大学中招募了143名学生。研究小组测量了他们的握力和与吸引力有关的解剖学变量——男性的肩臀比以及女性的腰臀比。每名志愿者同时还完成了一份有关性行为（包括发生第一次性接触的年龄以及性伴侣数目）和高中及初中阶段的侵略性行为的调查问卷。
结果显示，女性志愿者的HGS与性历史或社会行为之间并没有相关性。但具有高HGS的男性发生性行为的时间相对更早，并且具有更多的性伴侣，同时在高中更为好斗（尽管他们在初中并非如此）。根据Gallup的推断，支配其他人和较早及频繁交配是一些能够由基因传递的特征。他说：“我相信，HGS是健康的一个诚实指标。”此外，HGS与一个人的肌肉状况有关，而后者则与人的健康水平具有直接关系。研究小组在11月出版的《进化与人类行为》（Evolution and Human Behavior）杂志上报告了这一研究成果。
而其他专家则对这些研究结果抱有不同看法。英国中央兰开夏大学的进化心理学家John T. Manning便指出，这项研究并没有对志愿者的种族进行划分——在其他样本中，种族差异的平均分布能够使这种趋势减弱或增强。而根据Gallup的解释，大学校规禁止询问学生的种族，甚至要求匿名。
澳大利亚圣露西娅市昆士兰大学的进化心理学家Bill von Hippel指出，很多令人兴奋的发现都与侵略性行为有关。von Hippel表示，横行霸道被视为“一种低自尊和缺乏自信的产物”。实际上，这些数据表明，对于那些强壮的男性而言，这种行为是一种改变社会地位的方法。
英文原文：
Handshake: Window on Your Genes?
By Benjamin Lester
ScienceNOW Daily News
9 November 2007
A limp handshake might say more about a man than he'd like to admit. According to new research, a firm grip is an indicator of genetic fitness. The findings link grip strength to aggressive behavior and sexual history and might provide insight into the mindsets of bullies.
Hand grip strength (HGS) is an inherited trait; about 65% of a person's grip strength is genetically determined, whereas the remaining 35% depends on training and developmental factors such as nutrition. Past studies have connected HGS to various measures of physical condition, including bone density and longevity. "It's a ubiquitous measure of health and vitality," says evolutionary psychologist Gordon Gallup of the University at Albany in New York state.
To find out whether HGS also reflects sexual and social behaviors, Gallup and his colleagues recruited 143 undergraduates from the university. The team measured their grip strength and anatomical variables linked to attractiveness--shoulder-to-hip ratio for men and waist-to-hip ratio for women. Each participant also completed a survey about sexual history (including age at first sexual encounter and number of partners) and middle and high school bullying behaviors.
The female participants showed no correlations between HGS and sexual history or social behaviors, the team reports in this month's issue of Evolution and Human Behavior. But men with high HGS started having sex sooner, reported more sexual partners, and were more aggressive during high school (although not middle school). According to Gallup, asserting dominance over others and mating early and often are attributes that help pass along one's genes. "Our conclusion is that hand-grip strength is an honest indicator of fitness," he says, adding that whereas HGS is related to overall muscularity, the latter is "nowhere near?as closely linked to health as is HGS.
Other experts have varying takes on the results. Evolutionary psychologist John T. Manning of the University of Central Lancashire in the United Kingdom frets that the study did not control for the ethnicity of the participants; racial differences in average size could make the trends weaker or stronger in other sample groups. (According to Gallup, university regulations prohibit asking about race, even anonymously.)
Evolutionary psychologist Bill von Hippel of the University of Queensland in St. Lucia, Australia, says that the most exciting finding is the bullying link. Bullying is seen as "a product of low self-esteem and self-doubt," says von Hippel. These data suggest that, instead, it's a method of jockeying for status, chosen by strong men who excel at it.
