red-headed stepchild

[sagehen]

>samclem:
>> I can understand that a stepchild might be
>>treated poorly, but why the red-headed?  Were red heads thought less of in
>>history?
> Doug Wilson:
>Why "red-headed"? My speculation is that this intensifier reflects a
>traditional superstitious aversion to redheads.
~~~~~~~~~
Given that the genetics of hair color is complicated and generally
ill-understood,
the fact that red-headedness  can pop up unexpectedly in families where
other coloring predominates could occasion suspicion about parentage.  This
alone might account for traditional prejudice against red-headedness that
seems to occur in many societies.
A. Murie