As a consequence, he reasoned that because parents tend to invest less in boys – because more boys die before the end of the period of parental care – there is a higher rate of male births to equalise parental investment in each sex.
由此，他推论出因父母趋于更少的在男孩上投资-因为更多的男孩在亲代抚育周期结束前死亡-存在较高的男性死亡率以均衡亲代在每个性别的投资。