2015考研英语阅读双胞胎母亲更幸福_大学英语阅读

2015考研英语阅读双胞胎母亲更幸福

　　为了评估人口过渡的影响，这两名研究员分头对在1870年前和在这时及之后进行生产的妇女进行取样。结果公布在英国皇家学会学报上以证明他们的假说。在1870年前生产双胞胎的母亲平均比生一个的多生1.9个孩子。这在1870年后就变为多于2.3 个了。更重要的是，从一个逐渐发展的角度来看，她们的孩子会更成熟。比起其她母亲来说，在1870年以前生育双胞胎的母亲会有多于1.24个孩子，这些孩子更能活到18岁。之后这个数据变成了1.56。

　　Of course, having twins automatically increases a mothers lifetime fertility by one, relative toher number of pregnancies. But, since few women have twins more than once, the data implythat mothers of twins are more productive, even ignoring that effect. Moreover, they alsooutperformed the mothers of singletons on a range of other reproductive measures, includingintervals between births and the age at which they gave birth to their last child.

　　当然，拥有双胞胎无意识的增强了母亲一生的生育力，这也和母亲的怀孕时间有关。但是如果很少妇女能多于一次的生产双胞胎，那么数据显示双胞胎的母亲拥有更好的生育力，甚至可忽视其影响。此外，她们也超过一个母亲的其她生育价值，包括生育之间的间歇和生育最后一个孩子的年龄。

　　Most strikingly, the pre-1870 group of mothers of twins actually lived longer than those whowere not thus blessed. They were, in other words, simply healthier. This suggests that, inevolutionary terms at least, twins are far from a curse. On the contrary, they are indeed themark of a supermum.