Mothers who have complained through the centuries that their sons will be the death of them may be right?
几个世纪以来，母亲们都在抱怨儿子是她们的死神，真是这样吗？
A study published in the journal Science showsshavingsboys shortens a woman's life span. Each son takes an average of 34 weeks off a woman's life span, evolutionary biologist Samuli Helle and colleagues at the University of Turku found. On the other hand,shavingsdaughters adds, but only very slightly, to a woman's life span.
进化生物学家萨缪尔·赫勒和他在图尔库大学的同事在《科学》期刊上发表一篇研究报告说，生儿子会缩短母亲的寿命。每个儿子平均缩短一位女性34周的生命。另一方面，生女儿会略延长母亲的寿命。
Helle and colleagues looked at birth and marriage records of Sami* people from 1640 to 1870. "Our results suggest that giving birth to sons had a higher relative long-term survival cost for mothers than giving birth to and raising daughters," they wrote. There could be biological reasons for this. Studies show boys are physiologically more demanding to produce--they grow bigger and faster in the womb, and some studies show it takes a woman longer to get pregnant again aftershavingsa son than aftershavingsa daughter. Testosterone produced by the fetus could suppress the mother's immune system and perhaps make her more susceptible to disease.
赫勒和他的同事调查研究了拉普兰人从1640年到1870年的结婚和生育记录，并写道：“我们的研究表明，相比之下，生儿子比生女儿要消耗更多精力。”有生物学推论为证。研究表明生育男孩有更多生理需求——相对女孩而言，他们在子宫内成长的更大更快，并且还有研究表明生完男孩以后，母亲需要比生完女孩更长的时间再次怀孕。胎儿产生的男性荷尔蒙可能会抑制母亲免疫系统的发展，使她更容易生病。
There could be genetic or social differences among the Sami, who are distinct from their Finnish and Swedish neighbors, Helle said. But he does not think so. "There is no reason to believe that this effect would be only visible in Sami people," he said. "Generally, boys get on their mothers' nerves more than girls because they are running around, and girls are more willing to help their mothers."
赫勒说，或许人们认为由于基因遗传或社会生长环境不同，拉普兰人会与邻国的芬兰人和瑞典人有所区别，但他却不这样认为。他说：“一般说来，男孩儿比女孩儿更容易让母亲担心，因为他们总是到处跑，而女孩儿则乐意帮母亲做事。”