An LC at a nearby hospital made a display of artificial teats for her
staff.  She talked about how they all knew babies could show strong
preferences for one teat over another, refusing some shapes altogether;
 why should anyone think the human nipple would be the only one exempt from
preferences, especially since it, too, comes in such a vast array of shapes
and sizes.

She also talked with them about the effect of a "super-normal stimulus".
Some birds will abandon their own eggs in favor of similarly colored but
much bigger eggs - or will ignore their own young's gaping mouths in favor
of a more brightly colored or wider gaping mouth.  They are built to
respond to a certain stimulus - and the bigger the stimulus the stronger
their response, even if it means the response is totally maladaptive.  But
then, in a real world, those birds would simply never encounter a
super-normal stimulus.  It's interference that sets them up for
inappropriate responses.

In the same way, a baby is at risk of ignoring the normal stimulus in favor
of the super-normal stimulus of a bottle teat.

I thought her presentation (heard about it;  didn't see it) was as logical
and persuasive as any I've seen or read.
-Diane Wiessinger, LC in private practice, Ithaca, NY