Becky Krumwiede writes about the 5% figure:

Why *would* we expect that only a minute proportion of mothers in this
>country couldn't produce a full milk supply?  We've messed with mother nature
>for so long--most of our mothers didn't nurse for any length of time, who knows
>what drugs may have been given to our mothers when they were pregnant with us,
>we feed our meat-producing animals all kinds of hormones and drugs, we
spray our
>food with pesticides, and mess with pregnancy and birth!  Isn't it possible
that
>some of these factors might affect our ability to lactate?

Becky,
        We get up in arms because most of the people promoting this 5%
figure *don't* realize/admit that any of it is iatrogenic or culturally
based.  They insist that 5% of women everywhere just can't produce enough
milk, and that is has nothing to do with management or drugs or anything
else.  And this makes absolutely no sense evolutionarily.  At least, that's
why this zealot gets so up in arms.  Also because about 50% of women who
give up nursing in the first weeks post-partum just automatically assume
they're part of that 5% who just "can't" nurse for some biological reason
that has nothing to do with cultural practices.  I even heard one person,
when confronted with the information that in many many cultures there are 0%
of women with insufficient milk, suggest that it was the biological
superiority of Europeans over "primitive" peoples that led to this
difference.  I was so dumbfounded I couldn't even answer, and to this day I
don't understand why an inability to lactate would make one "superior."

Kathy Dettwyler