By Linda F. Palmer, DC
author Baby Matters
Reprinted from the Attachment Parenting International
News, Vol. 5, No. 2, 2002 ** Unedited by BPO staff
Human babies are born helpless, needing to
be entirely cared for and protected. Luckily, they are born
with all the necessary tools and "instructions" to attain such
care for themselves, and to become a loved and loving part of
their family and society. The ingrained neural and hormonal
interactions provided for parent and child to assist them in
this process are among the most powerful in nature. The hormonal
cues are clear and compelling and our instincts can provide
us with all the appropriate responses. Without taking great
efforts to avoid and ignore such urges, parents will naturally
follow the advice of their neurons and hormones, nurturing their
babies and maintaining physical closeness with them.
Once born, baby's hormonal control systems
and brain synapses begin to permanently organize according to
the human interactions she experiences. Unneeded brain receptors
and neural pathways are disposed of, while those appropriate
to the given environment are enhanced.
Oxytocin-a Bonding Hormone
Oxytocin is a chemical messenger released in the brain chiefly
in response to social contact, but its release is especially
pronounced with skin-to-skin contact. In addition to providing
health benefits, this hormone-like substance promotes bonding
patterns and creates desire for further contact with the individuals
inciting its release.
When the process is uninterrupted, oxytocin
is one of nature's chief tools for creating a mother. Roused
by the high levels of estrogen ("female hormone") during pregnancy,
the number of oxytocin receptors in the expecting mother's brain
multiplies dramatically near the end of her pregnancy. This
makes the new mother highly responsive to the presence of oxytocin.
These receptors increase in the part of her brain that promotes
maternal behaviors .
Oxytocin's first important surge is during
labor. If a cesarean birth is necessary, allowing labor to occur
first provides some of this bonding hormone surge (and helps
ensure a final burst of antibodies for the baby through the
placenta). Passage through the birth canal further heightens
oxytocin levels in both mother and baby.
High oxytocin causes a mother to become familiar
with the unique odor of her newborn infant, and once attracted
to it, to prefer her own baby's odor above all others'. Baby
is similarly imprinted on mother, deriving feelings of calmness
and pain reduction along with mom. When the infant is born,
he is already imprinted on the odor of his amniotic fluid. This
odor imprint helps him find mother's nipple, which has a similar
but slightly different odor. In the days following birth, the
infant can be comforted by the odor of this fluid.
Gradually over the next days, baby starts to
prefer the odor of his mother's breast, but continued imprinting
upon his mother is not food related. In fact, formula-fed infants
are more attracted (in laboratory tests) to their mother's breast
odor than to that of their formula, even two weeks after birth
.
By influencing maternal behavior and stimulating
milk "let down" (allowing milk to flow) during nursing, oxytocin
helps make the first attempts at breastfeeding feel natural.
Attempts at nursing during the initial hour after birth cause
oxytocin to surge to exceptional levels in both mother and baby.
Mothers who postpone nursing lose part of the ultimate hormone
high provided for immediately after birth. Powerful initial
imprinting for mother and baby is intended to occur chiefly
so that mother and baby will be able to find and recognize each
other in the hours and days after birth.
Yet a lifetime opportunity for bonding and
love is not lost if this initial window is missed. Beyond birth,
mother continues to produce elevated levels of oxytocin as a
consequence of nursing and holding her infant, and the levels
are based on the amount of such contact. This hormonal condition
provides a sense of calm and well being. Oxytocin levels are
higher in mothers who exclusively breastfeed than in those who
use supplementary bottles. Under the early influence of oxytocin,
nerve junctions in certain areas of mother's brain actually
undergo reorganization, thereby making her maternal behaviors
"hard-wired."
As long as contact with the infant remains,
oxytocin causes mother to be more caring, to be more eager to
please others, to become more sensitive to other's feelings,
and to recognize nonverbal cues more readily. Continued nursing
also enhances this effect. With high oxytocin, mother's priorities
become altered and her brain no longer signals her to groom
and adorn herself in order to obtain a mate, and thus a pregnancy.
Now that the child has already been created, mom's grooming
habits are directed toward baby. High oxytocin in the female
has also been shown to promote preference for whatever male
is present during its surges (one good reason for dad to hang
around during and after the birth). Prolonged high oxytocin
in mother, father, or baby also promotes lower blood pressure
and reduced heart rate as well as certain kinds of artery repair,
actually reducing lifelong risk of heart disease .
Although baby makes her own oxytocin in response
to nursing, mother also transfers it to the infant in her milk.
This provision serves to promote continuous relaxation and closeness
for both mother and baby. A more variable release of oxytocin
is seen in bottle-fed infants, but is definitely higher in an
infant who is "bottle-nursed" in the parents' arms rather than
with a propped bottle.
Persistent regular body contact and other nurturing
acts by parents produce a constant, elevated level of oxytocin
in the infant, which in turn provides a valuable reduction in
the infant's stress-hormone responses. Multiple psychology studies
have demonstrated that, depending on the practices of the parents,
the resulting high or low level of oxytocin will control the
permanent organization of the stress-handling portion of the
baby's brain -- promoting lasting "securely attached" or "insecure"
characteristics in the adolescent and adult. Such insecure characteristics
include anti-social behavior, aggression, difficulty forming
lasting bonds with a mate, mental illness, and poor handling
of stress.
When an infant does not receive regular oxytocin-producing
responsive care, the resultant stress responses cause elevated
levels of the stress hormone cortisol. Chronic cortisol elevations
in infants and the hormonal and functional adjustments that
go along with it are shown in biochemical studies to be associated
with permanent brain changes that lead to elevated responses
to stress throughout life, such as higher blood pressure and
heart rate. Mothers can also benefit from the stress-reducing
effects of oxytocin-women who breastfeed produce significantly
less stress hormone than those who bottle-feed .
Nor are fathers left out of the oxytocin equation.
It has been shown that a live-in father's oxytocin levels rise
toward the end of his mate's pregnancy. When the father spends
significant amounts of time in contact with his infant, oxytocin
encourages him to become more involved in the ongoing care in
a self-perpetuating cycle. Oxytocin in the father also in-creases
his interest in physical (not necessarily sexual) contact with
the mother. Nature now provides a way for father to become more
interested in being a devoted and satisfied part of the family
picture through his involvement with the baby.
With all of its powers, oxytocin is but one
of a list of many chemicals that nature uses to ensure that
baby finds the love and care he needs.
Vasopressin & Protection
Although present and active during bonding in the mother and
infant, vasopressin plays a much bigger role in the father.
This hormone promotes brain reorganization toward paternal behaviors
when the male is cohabitating with the pregnant mother. The
father becomes more dedicated to his mate and expresses behaviors
of protection.
Released in response to nearness and touch,
vasopressin promotes bonding between the father and the mother,
helps the father recognize and bond to his baby, and makes him
want to be part of the family, rather than alone. It has gained
a reputation as the "monogamy hormone." Dr. Theresa Crenshaw,
author of The Alchemy of Love and Lust, says, "Testosterone
wants to prowl, vasopressin wants to stay home." She also describes
vasopressin as tempering the man's sexual drive.
Vasopressin reinforces the father's testosterone-promoted
protective inclination regarding his mate and child, but tempers
his aggression, making him more reasonable and less extreme.
By promoting more rational and less capricious thinking, this
hormone induces a sensible paternal role, providing stability
as well as vigilance.
Prolactin & Behavior
Prolactin is released in all healthy people during sleep, helping
to maintain reproductive organs and immune function. In the
mother, prolactin is released in response to suckling, promoting
milk production as well as maternal behaviors. Prolactin relaxes
mother, and in the early months, creates a bit of fatigue during
a nursing session so she has no strong desire to hop up and
do other things.
Prolactin promotes caregiving behaviors and,
over time, directs brain reorganization to favor these behaviors
. Father's prolactin levels begin to elevate during mother's
pregnancy, but most of the rise in the male occurs after many
days of cohabitation with the infant.
As a result of hormonally orchestrated brain
reorganization during parenthood, prolactin release patterns
are altered. It has been shown that fathers release prolactin
in response to intruder threats, whereas childless males do
not. On the other hand, nursing mothers do not release prolactin
in response to loud noise, whereas childless females do. In
children and non-parents, prolactin surges are related to stress
levels, so it is generally considered a stress hormone. In parents,
it serves as a parenting hormone.
Elevated prolactin levels in both the nursing
mother and the involved father cause some reduction in their
testosterone levels, which in turn reduces their libidos (but
not their sexual functioning). Their fertility can be reduced
for a time as well. This reduction in sexual activity and fertility
is entirely by design for the benefit of the infant, allowing
for ample parental attention and energy. When the father is
intimately involved with the infant along with the mother, there
should be some accord between the desires of the two, and oxytocin
and other chemicals provide for heightened bonding and non-sexual
interest in each other, which serves to retain a second devoted
caretaker for the infant.
Opioids & Rewards
Opioids (pleasure hormones) are natural morphine-like chemicals
created in our bodies. They reduce pain awareness and create
feelings of elation. Social contacts, particularly touch-especially
between parent and child- induce opioid release, creating good
feelings that will enhance bonding. Odor, taste, activity, and
even place preferences can develop as the result of opioid release
during pleasant contacts, and eventually the sight of a loved
one's face stimulates surges. Opioid released in a child's brain
as a conditioned response to a parent's warm hugs and kisses
can be effective for helping reduce the pain from a tumble or
a disappointment.
Parents "learn" to enjoy beneficial activities
such as breastfeeding and holding, and infants "learn" to enjoy
contact such as being held, carried, and rocked, all as a response
to opioid release. Babies need milk, and opioids are nature's
reward to them for obtaining it, especially during the initial
attempts. The first few episodes of sucking organize nerve pathways
in the newborn's brain, conditioning her to continue this activity.
This is the reason that breastfed babies sometimes have trouble
if they are given bottles in the newborn nursery-early exposure
to bottles creates a confusing association of pleasure with
both bottle nipples and the mother's breast. In fact, any incidental
sensations experienced during rocking, touching, and eating
that aren't noxious can become part of a child's attachment
and will provide comfort. It could be the warmth of mother's
body, father's furry chest, grandma's gentle lullaby, a blanket,
or the wood-slatted side of a crib.
Prolonged elevation of prolactin in the attached
parent stimulates the opioid system, heightening the rewards
for intimate, loving family relationships, possibly above all
else. Just as with codeine and morphine, tolerance to natural
opioids can occur, which will reduce the reward level for various
activities over time. But this is not a problem for attached
infants and parents, because higher levels of oxytocin, especially
when created through frequent or prolonged body contact, actually
inhibit opioid tolerance , protecting the rewards for maintaining
close family relationships. On the other hand, consuming artificial
opioid drugs replaces the brain's need for maintaining family
contacts.
Once a strong opioid bonding has occurred,
separation can become emotionally upsetting, and in the infant
possibly even physically uncomfortable when opioid levels decrease
in the brain, much like the withdrawal symptoms from cocaine
or heroin. When opioid levels become low, one might feel like
going home to hold the baby or like crying for a parent's warm
embrace, depending on your point of view. Sometimes alternate
behaviors are helpful. For instance, thumb-sucking can provide
some relief from partial or total withdrawal from a human or
rubber nipple and can even provide opioid-produced reminiscences
for a time.
Norepinephrine & Learning
Breastfeeding also causes dopamine and its product, norepinephrine
(adrenaline), to be produced, which help maintain some of the
effects of the early bonding. They enhance energy and alertness
along with some of the pleasure of attachment.
Norepinephrine helps organize the infant's
stress control system, as well as other important hormonal controls
in accordance with the nature of the early rearing experiences.
It promotes learning about the environment-especially learning
by memorization that is carried out by oxytocin, opioids, and
other chemical influences.
Pheromones & Basic Instincts
How does the man's body know to initiate hormonal changes when
he is living with a pregnant female? How can an infant accurately
interpret mother's "odors" that adults often can barely detect?
The answer is pheromones. Among other things, pheromones are
steroid hormones that are made in our skin. Our bodies are instinctually
programmed to react accordingly when we detect these pheromones
around us.
Newborns are much more sensitive to pheromones
than adults. Unable to respond to verbal or many other cues,
they apparently depend on this primitive sense that controls
much of the behavior of lower animals. Most likely the initial
imprinting of baby to odors and pheromones is not just a matter
of preferring the parents' odors, but is a way nature controls
brain organization and hormonal releases to best adapt baby
to its environment. Baby's earliest, most primitive experiences
are then linked to higher abilities such as facial and emotional
recognition. Through these, baby most likely learns how to perceive
the level of stress in the caretakers around her, such as when
mother is experiencing fear or joy. Part of an infant's distress
over separation may be caused by the lost parental cues about
the safety of her environment. Of course the other basic sensation
an infant responds to well is touch, and coincidentally, body
odors and pheromones can only be sensed when people are physically
very near each other.
What the World Needs Now . . .
Infants universally cry when laid down alone. If we allow ourselves
to listen, our neurons and hormones encourage us in the proper
response. Babies are designed to be frequently fed in a fashion
that requires skin-to-skin contact, holding, and available facial
cues. Beneficial, permanent brain changes result in both parent
and infant from just such actions. Contented maternal behaviors
grow when cues are followed. The enhancement of fatherhood is
strongly provided for as well. A father's participation encourages
his further involvement and creates accord between father and
mother. Frequent proximity and touch between baby and parents
can create powerful family bonding-with many long-term benefits.
Sadly, over the last century parents have been
encouraged by industry-educated "experts" to ignore their every
instinct to respond to baby's powerful parenting lessons. Psychologists,
neurologists, and biochemists have now confirmed what many of
us have instinctually suspected: that many of the rewards of
parenthood have been missed along the way, and that generations
of children may have missed out on important lifelong advantages.
Endnotes
1. T.R. Insel, "Oxytocin - a
neuropeptide for affiliation: evidence from behavioral, receptor
autoradiographic, and comparative studies," Psychoneuroendocrinology
17, no. 1 (1992): 3-35.
2. H. Varendi et al., "Soothing
effect of amniotic fluid smell in newborn infants," Early Hum
Dev (Estonia) 51, no. 1 (Apr 1998): 47-55.
3. R.H. Porter et al., "An assessment
of the salient olfactory environment of formula-fed infants,"
Physiol Behav 50, no. 5 (Nov 1991): 907-11.
4. S.S. Knox and K. Uvnas-Moberg,
"Social isolation and cardiovascular disease: an atherosclerotic
pathway?" Psychoneuroendocrinology 23, no. 8 (Nov 1998): 877-90.
5. M. Altemus et al., "Suppression
of hypothalamic-pituitary-adrenal axis responses to stress in
lactating women," J Clin Endocrinol Metab 80, no. 10 (Oct 1995):
2965-9
6. R.S. Bridges, "The role of
lactogenic hormones in maternal behavior in female rats," Acta
Paediatr Suppl 397 (Jun 1994): 33-9.
7. G.L. Kovacs et al., "Oxytocin
and addiction: a review," Psychoneuroendocrinology (Hungary)
23, no. 8 (Nov 1998): 945-62.
8. G.W. Kraemer et al., "A longitudinal
study of the effect of different social rearing conditions on
cerebrospinal fluid norepinephrine and biogenic amine metabolites
in rhesus monkeys," Neuropsychopharmacology 2, no. 3 (Sep 1989):
175-89
© Copyright 2002 Dr. Linda Folden
Palmer, All rights reserved.
Linda Folden Palmer, DC, is the author of
the healthy parenting book: Baby Matters, What Your Doctor
May Not Tell You About Caring for Your Baby. She provides
telephone consultations for colic, lactation difficulties,
child nutrition, food allergy issues, and infant sleep challenges.
Promoting attachment and natural parenting principles, she
is dedicated to raising awareness about how powerfully early
parenting and healthcare choices can influence a child's mental
and physical outcomes. Find her at www.babyreference.com
