Would you like to know if your child is set to stand head and shoulders above the rest? Or if they're likely to stay diminutive¹ into adulthood²?

想知道你家孩子将来的身高会鹤立鸡群吗？还是会一直这么矮下去？

There is an easy (although fallible) mathematical equation that can help you predict how tall your child will be.

有一个简单（但不一定靠谱）的数学公式可以帮你预测孩子未来的身高。

The formula, which has been used since the 1970s and was revealed in the New York Times, predicts that 'most (but not all) children will reach a height somewhere within a fairly small range that can be estimated by the average combined heights of their parents.'

该公式自上世纪70年代开始流行，发端于《纽约时报》。公式称，“根据父母的平均身高总和，可以推算出孩子身高的波动范围，这个波动范围很小。大部分（并非所有）孩子适用这个规律。”

How does it work?

具体怎么算呢？

BOYS

男孩

Add the heights of both parents plus 5in (13cm) and divide by two.

父母身高相加，总和再加5英寸（13厘米），用结果除以2。

比如父亲1米76，母亲1米65，那儿子的身高就是（1.76 + 1.65 + 0.13）/ 2 = 1.77，即1米77。

GIRLS

女孩

Add the heights of both parents minus 5in (13cm) and divide by two.

父母身高相加，总和减去5英寸（13厘米），用结果除以2。

比如父亲1米76，母亲1米65，那女儿的身高就是（1.76 + 1.65 - 0.13）/ 2 = 1.64，即1米64。

There is a more complicated formula for extreme differences in parental³ height.

父母身高差距比较大的话，需要用另一个复杂点儿的公式。

These predictions are by no means completely reliable, however, as environmental factors such as nutrition play a big part in determining human height.

不过这种预测不可能完全准确，因为还要考虑环境因素，比如营养状况就会对身高发挥重要影响。

Genetics is estimated to account for between 60 and 80 per cent of one's final height.

基因约占所有影响身高因素的60%至80%。

A study of 8,798 pairs of Finnish twins conducted in 2000 found that genetics accounted for 78 per cent of height in adult men and around 75 per cent in women.

2000年，一项针对8798对芬兰双胞胎的研究显示，基因对男性身高的影响达78%，对女性达75%。

However, as we all know not all children born to the same couple will be the same height.

不过正如我们所知，同一对父母，其所有孩子的身高不一定会是相同的。

Science shows that height tends to decrease in younger siblings⁴.

科学研究证明，后出生的孩子身高会倾向于变矮。

Another popular method for predicting height is to double a boy's height at age two or a girl's height at 18 months.

另一个著名的预测未来身高的方法是：男孩两岁时的身高乘以2；女孩18个月时的身高乘以2。

Most children will reach an adult height within 4in (10cm) of this estimation.

大部分孩子长大后的身高会在这个预估数值的上下4英寸（10厘米）范围内波动。