VOA慢速英语:Biology May Keep New Fathers Close to Home

A few months ago, government researchers released the latest American Time Use Survey. It included the average time per day that Americans spent providing child care between two thousand six and two thousand ten.
几个月前，政府研究人员公布了最新的美国时间利用调查报告。它包括了2006年至2010年间美国人每天花费在照顾儿童方面的时间。

Among adults living with children under age six, women spent one hour and six minutes a day providing physical care. This is care like bathing or feeding a child. Men spent twenty-six minutes.
在和6岁以下儿童生活在一起的成年人中，女性每天花费1小时6分钟的时间提供身体护理，这种护理就像给小孩洗澡或喂食。男性则花费了26分钟。

Yet a new study suggests that men are biologically designed to care for their children. It confirmed that testosterone levels drop after men become fathers.
然而，一项新的研究表明，男性从生物学上讲是来照顾小孩的。该报告证实，男性在做父亲之后睾丸激素水平降低。

Testosterone is the main sex hormone responsible for the changes when a boy develops into a man. Women also produce testosterone but in much lower amounts.
睾丸激素是负责男孩向男人转变过程中一种主要的性激素。女性也分泌睾丸激素，但是数额低很多。

Earlier studies showed that fathers have lower levels of testosterone than childless men. Christopher Kuzawa at Northwestern University in Evanston, Illinois, says there are at least two possible explanations.
先前的研究表明，做父亲的男性睾丸激素的水平比没有子女的男性低。伊利诺伊州埃文斯敦西北大学的Christopher Kuzawa说，至少有两种可能的解释。

CHRISTOPHER KUZAWA: “Is it that fatherhood reduces your testosterone? Or do men with low testosterone to begin with, are they more likely to become fathers? And so what we did is, we followed men through time and measured their hormones before and after they became fathers.”
Christopher Kuzawa：“难道成为父亲会降低睾丸激素水平？还是睾丸激素水平比较低的男性更有可能成为父亲？因此，我们所做的是，我们一直对接受调查的男性进行跟踪，测量他们在成为父亲前后的荷尔蒙水平。”

Professor Kuzawa is a biological anthropologist. He and other researchers used information from a long-term study of men in the Philippines. That study measured their testosterone levels in two thousand five and two thousand nine.
Kuzawa教授是一位生物学人类学家。他和其他研究人员使用的信息来自对菲律宾对男性进行长期研究收集。这项研究测量了这些男性在2005年至2009年间的睾丸激素水平。

Some of the men were childless; others became fathers during that time.
其中一些男性没有子女，其他人在此期间成为父亲。

CHRISTOPHER KUZAWA: “And those are the men where we see the largest decline in testosterone.”
Christopher Kuzawa：“我们看到这些男性的睾丸激素水平降幅度最大。”

The study found that testosterone levels dropped by about half immediately after the birth of a child, then rose some. Men who were active in child care produced less than those who were not active.
研究发现，孩子出生之后，这些男性的睾丸激素水平立即降低近一半，而后再上升一些。积极照顾孩子的男性比不积极的睾丸激素更少。

Testosterone levels may drop in fathers to get them to pay more attention to parenting than to reproducing. But Professor Kuzawa says there are other good reasons as well.
男性睾丸激素水平降低可能是为了让他们更集中精力于照顾小孩，而不是生殖方面。但是Kuzawa表示，也许还有其他的原因。

CHRISTOPHER KUZAWA: “Having high levels of testosterone can increase your risk for diseases like prostate cancer [and] testicular cancer.  Also, testosterone can suppress the immune system so that you’re less capable of fending off pathogens.”
Christopher Kuzawa：“睾丸激素水平高会增加前列腺癌和睾丸癌等疾病的风险。此外，睾丸激素还会抑制免疫系统，导致抵抗病原体的能力下降。”

The study is in the Proceedings of the National Academy of Sciences.
该研究发表在国家科学院院刊上。

Studies have shown a similar drop in other mammals and in birds after mating periods to allow for care giving. Animal studies have shown that the greater the involvement of males, the lower their testosterone levels.
有研究表明，其他哺乳动物和鸟类在交配期后荷尔蒙水平也会下降，使父母可以照顾孩子。动物研究表明，雄性参与照顾孩子的程度越高，睾丸激素水平越低。

We asked Thomas McDade, another author of the study, if testosterone levels also drop in men who adopt children. He says that is an interesting question and the “next obvious thing to study.”
我们问了这份研究的另外一位作者Thomas McDade，收养孩子的男子睾丸激素水平是否也会降低。他说，这是很有趣的问题，这就是他们接下来的研究要做的。