To learn whether they also had an effect on their sisters' reproductive success, researchers investigated 197 women and 76 men. They ranged in age from 18 to 75, and all but 10 - seven of them women - had siblings.

为了了解兄弟的存在是否会影响女孩子的生殖情况，研究人员调查访问了197位女性和76位男性。他们年龄在18岁到75岁之间，除了10人没有兄弟姐妹外（10人中有7位是女性），其他人都不是独生子女。

"This research helps us to better understand how family dynamics influence development," said researcher Fritha Milne, a behavioral ecologist at the University of Western Australia.

“该项研究有助于我们更好地理解家庭动态如何影响生殖发育，”西澳大学行为生态学家弗利沙-米尔恩说道。