Throughout history, human hair has been the subject of much vanity, research, and stereotyping. Hair traits and associated medical and social implications influence our perceptions of each other and ourselves. In this sometimes hair-raising account, we explore some of the most fascinating facts in the study of human hair.
纵观历史，人类的头发一直是虚荣心、科学研究和刻板印象的主题。头发的特征和它在医学及社会交际上的隐含意义影响着我们对他人和自我的认知。在这份有点令人恐惧的报告中，我们探究了一些关于人的头发最令人感兴趣的事实。

1.Blonde Women Have More Estrogen
1.金发女郎体内有更多的雌激素

Hair color might not instinctively seem applicable as an indicator of human traits. However, hair color is an outward indicator and genetic phenotype component that means different things according to the gender of the person bearing it. For example, blondes are sometimes perceived as especially feminine. In fact, scientific investigation indicates that blondes have higher levels of estrogen than other females.Blondes may thus have finer features and a more "youthful" personality than darker-haired women. Surprisingly, blond hair does not seem to relate as much, if at all, to male hormone levels, although more research could always uncover surprises. Both male and female blonds have more hair, with an average of 130,000 hairs, compared to 100,000 for brunettes and 80,000 for redheads.
头发的颜色通常不会被当做人类特征的表现。但其实，头发的颜色既是一种外在的展现，也是基因显性成分的表现，并且根据携带者的性别不同，会有不同的表现。例如，金发美女通常被认为是极具女人味的。事实上，科学研究发现，金发美女比一般女性拥有更多的雌激素。因此，金发美女可能比那些深色头发的女性具有更出众的外表和更“朝气蓬勃”的个性。令人吃惊的是，金发似乎与男性荷尔蒙水平的联系并不很大，如果有的话，尽管更多的研究总是能有令人惊喜的发现。金发的男性和女性平均有130,000根头发，明显多于深色头发人的100,000根和红头发人的80,000根。

2.Redheads Get Hurt Easily
2.红头发的人更容易受伤

Redheads are often stereotyped as hot-tempered. While the jury may still be out on that particular personality trait, the science is fairly strong on the fact that redheads are definitely prone to getting sore—referring, of course, to how they perceive pain. Dentists and scientific researchers have noted that natural redheads are in fact more sensitive to pain than blonds or brunettes.At the same time, redheads are hit with an unfair and ironic combination—they are less sensitive to the effects of painkillers than blonds or brunettes. Redheads often avoid going to the dentist, and it turns out that a dose of painkillers 20 percent higher than the norm may be needed to properly inhibit their pain reception, according to a study recently published in the British Medical Journal. Redheads are also more susceptible to skin cancer, and, oddly, never develop gray hair. Redheads may eventually turn blondish, and then pure white.
红头发的人经常被认为脾气火爆，这应该是大众长久以来对这种类型的人的特点所持有的判断。科学也清楚有力地证明了这一点：红头发的人更容易发怒，当然这涉及到他们如何看待痛苦。牙医和科学研究者已经注意到，事实上红头发的人比金发或者深色头发的人对痛苦更敏感。同时，红头发的人是一个饱受不公平待遇和讽刺的集合体——比起金发或者深色头发的人，他们对止痛药比较不敏感。据一个近期发表在《英国医学杂志》（the British Medical Journal）的研究表明，红头发的人通常逃避去看牙医，这样造成的结果是，他们要用比普通人多20%剂量的止痛药才能止住疼痛。另外，红头发的人更容易患上皮肤癌，而且他们从来不长灰色的头发。他们最终可能变成金发，然后再变成满头白发。

3.Learning Disabilities And Hair Color
3.学习障碍症和头发颜色

Blond hair and blue eyes might be seen as a striking combination, but they could also be correlated with an increased incidence of certain medical conditions. In a study of 50 learning disabled children, 20 percent were blond. However, only 11 percent of non-disabled children were blond. The blond hair and blue eyes combination is also often seen in patients affected by phenylketonuria, where phenylalanine builds up in the body. Behan et al. (1985) suggest a higher rate of blue-eyed blonds in the dyslexic population (they were also more likely to be left-handed). Another study noted a slightly increased incidence of learning disabilities reported by blond professionals. It is believed that melanin may play a role in the development of neural circuits, and some blonds may be more subject to certain conditions as a result of their reduced melanin levels.
金发和碧眼也许看起来是最美妙的结合，但是它们也和特定的医疗条件下增加的发病率有关。在一项研究中，50个有学习障碍的孩子中，20%的是金发。相反，在没有学习障碍的孩子中仅仅有11%的是金发。金发和碧眼的组合在苯丙酮酸尿症患者中是常见的，这些患者体内的苯基丙氨酸积累过多。Behan等人（1985）认为大部分金发碧眼的人有诵读困难症（他们很多是左撇子）。另一项研究显示，金发研究专家认为学习障碍症的发病率在金发碧眼的人中有轻微的增长。众所周知，黑色素在神经回路的发展中起着重要作用，一些金发的人由于缺少黑色素，会对某些特定条件更加抗拒。

4.Baldness Is Linked To Heart Disease
4.头顶脱发和心脏病有关

The loss of hair, whether as a result of a medical condition or aging, is often a great source of concern. It is usually males who go bald, while women almost always keep their hair, a fact related to testosterone levels. Baldness might seem cosmetic, but a recent medical study of 40,000 men has linked balding to a much greater risk of coronary heart disease. The risk of heart disease in men with male pattern baldness was found to be 70 percent greater than in non-balding males. Different levels of baldness carried differing risk levels, from 18 percent at mild to 48 percent for serious balding. The correlation between top of the head baldness and heart disease is believed to relate to multiple factors, potentially including insulin and hormone-related variables. Interestingly, a receding hairline and hair-loss away from the top of the head was not associated with heart disease.
脱发，不管是药物还是年龄原因造成，都是人们忧虑的一大根源。最近一项医学研究调查了4万名头顶脱发的男性，结果表明秃顶的人有很大可能患上冠心病。秃顶男性比正常男性患心脏病的风险高70%。另外，秃顶的程度不同，患病的风险也不同，轻微秃顶的男性患病几率为18%，而严重秃顶的男性患病几率则高达48%。这种头部秃顶和心脏病的联系和许多因素有关，包括体内胰岛素和雌激素相关含量的变化。有趣的是，逐渐后退的发际线和头顶部分以外的脱发和心脏病没多大关系。

翻译:王珊 来源:listverse