Unless they're monozygotic or identical twins.

除非他们是同卵双胞胎。

Identical, or monozygotic, twins share 99.99 percent of their DNA.

一半是一样，全是一样。同卵双胞胎的基因相似度高达99.99%。

Are monozygotic twins just as similar as dizygotic twins?

单卵双生子和双卵双生子一样相似吗？

Suppose you find that monozygotic twins are much more similar than dizygotic twins.

假设你发现单卵双生子比双卵双生子更相似。

For instance, monozygotic twins look more alike than dizygotic twins and maybe they have different and--they have more similar environments because of this similarity in appearance.

比如， 单卵双生子的相貌更相似， 可能是因为他们有着不同的、更相似的环境。

So, if you do the standard behavioral genetic tests, and you by now know how to do them--you'd look for differences between monozygotic and dizygotic twins, you'd do the adoption comparison--you know adopted siblings and biological siblings.

所以， 如果你做标准的行为基因测试，你现在已经知道如何做它们了——你会寻找同卵双胞胎和异卵双胞胎之间的差异，你会做收养比较——你知道收养的兄弟姐妹和亲生兄弟姐妹。