Dear LactNetters, I wrote this in response to an e-mail from a doctor in
Switzerland (not our friend Jim Akre from WHO) who took offense at my
statement in my chapter on weaning from the book that it wasn't
normal/natural for human children to suck their thumbs or fingers, and that
such behavior was a sign of a child whose needs weren't being met at the
breast.  He countered that self-comforting was a good talent for
infants/children, and that even fetuses in the womb sucked their thumbs.
When I finished writing this I decided maybe you'all would like to read it.

Re the thumb-sucking issue -- it is certainly true that ultrasound and
photography in the womb shows fetuses sucking their thumbs, but then
breasts/nipples aren't available in the womb, but the suckling instinct is
clearly present from an early age.  Once the baby is born, however, the
suckling instinct is supposed to be directed toward the breast, to get the
child nutrition and immunities, and the sucking itself lowers the baby's
heart rate and blood pressure.  While it can be *convenient for the parents*
to have the baby suck on their thumb or fingers or pacifier (like in the car
on trips, or when mother is trying to cook dinner) it nevertheless is clear
from both cross-cultural and cross-species field studies that, given
complete contact with mother and free access to the breast on demand, human
children (and young of our close relatives, the great apes) do not suck on
their thumbs or fingers.  I never saw a child in Mali sucking its thumb or
fingers, in almost three years of watching/observing/studying mother-child
interactions.  Likewise, thumb sucking is reported to be completely absent
from cultures such as the Navajo, in highland Papua New Guinea, Ecuador, the
Peruvian Andes, Mexico, Nepal, India, Tanzania, Botswana, and South Africa.
A number of other ethnographic studies of breastfeeding don't mention thumb
sucking one way or another.  Thumb sucking is also absent from the great
apes (chimpanzees and gorillas) except among zoo nusery raised animals.  I
think it is clear that human children have sucking instincts that can
persist until 7 or 8 years of age, or even longer, and must meet those needs
somehow -- through thumb, finger, or pacifier, if not allowed to meet them
at the breast.  But I also think that meeting those needs at the breast is
the "normal/natural" context or situation, and involves not just lowering
the heart rate/blood pressure, but also the transfer of nutrients and
immunities, as well as helping the child with thermoregulation from being in
contact with its mother's body.  It may be that thumb/finger/pacifier
sucking "tricks" the child into being "pacified" for the time being, even to
the extent of reducing the time spent at the breast.  That doesn't mean it
is good for the child.  In fact, finger and thumb sucking often lead to
orthodontic problems.  In the U.S. orthodontists even have evil-looking
devices they will install in a child's mouth to make it painful for the
child to continue sucking their thumb/fingers, in order to break them of
this habit.  If the child were allowed to meet those sucking needs at the
breast, it wouldn't lead to orthodontic problems (in fact, just the
opposite, with less orthodontic problems in long-term breastfed kids).  Any
time you force the child to rely on their own resources prematurely, you
must expect deleterious consequences.  When the child's needs are met
through person-to-person interaction with its mother, you establish the
primacy of social contact, and the interdependence of human beings, rather
than encouraging/forcing the child to meet its needs by itself.

This may be a crude analogy, but consider this:  If you have two adults,
married to each other, who have all the children they want and don't want to
get pregnant, but still have strong sex drives, would you consider it
*better* if they each went into a separate room and masturbated?  This would
certainly allow them to "self comfort" and would make them independent and
autonomous, so that one wouldn't have to wait until the other was ready or
"in the mood."  Would you really consider this an improvement?





Katherine A. Dettwyler, Ph.D.
Associate Professor of Anthropology
Specialist in infant feeding and growth of children
Texas A&M University
e-mail to [log in to unmask]
(409) 845-5256
(409) 778-4513