We do not know which behavioural traits are inherited and which acquired.

我们不知道哪些行为特征是遗传的，哪些是后天养成的。

This was true whether applied to a congenital defect, such as syndactyly, or an acquired defect, such as a burn contracture.

把它们应用于诸如并指的先天缺损或是烧疤痕挛缩类后天缺损的修复，往往都没错。