Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
by Sarah Blaffer Hrdy; New York: Ballantine Books, 1999.
Part Three: An Infant’s-Eye View: Chapter 15: Born to Attach
Bowlby Examines Darwin’s Childhood
1. Darwin was not prepared to imagine mothers as multifaceted
strategists. His mother died when he was 8—fear of loss.
2. This constrained his ability to think about the full range of
selection pressures that would have acted upon infants in the
evolutionary past.
Connoisseurs of Mothering
1. Bowlby proposed that all primates are born preprogrammed to
form a powerful emotional attachment to their mother or other
primary attachment figure to whom the infant strove to stay close
at all times.
2. Infants are exquisitely sensitive to signals of maternal
commitment. Will she stay close or disappear?
3. If human mothers were automatically nurturing, their infants
would not need to be so attuned and keenly discriminating.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
Harmonious but Also Discordant Interests
1. There are innate conflicts of interest between a mother and the
rapidly growing fetus within her, between an infant who desires
to nurse longer and a mother who is ready to wean it.
2. In the human case, the costs of rearing infants (and then children)
go on and on, long past weaning.
3. An infant had to be appealing in order to extract more rather than
less care from his mother, or in extreme cases to be cared for at
all.
Chapter 16: Meeting the Eyes of Love
Where does the Need to Attach Come From? (Harry Harlow)
1. Harry Harlow was doing “bizarre” experiments on “mother love”
that at the University of Wisconsin.
2. Harlow would provide infant rhesus macaques a choice between
terrycloth-covered but nippleless “mother-surrogates” that
permitted infants to cling to a warm, soft surface, OR similarly
configured dolls made of bare wire but equipped with milk
bottles.
3. The baby monkeys spent only as much time on the wire mothers
as was necessary to feed before scrambling back to the comfort of
the soft surrogates, where they felt more secure.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
4. Clinging to a surrogate mother had everything to do with this
notion of “security” and little to do with satisfying hunger.
Effects of Separation in Other Primates (Macaque Experiments)
1. A number of experiments were done in which five to six-monthold rhesus macaques were separated from their mothers for
either one six-day period, two such periods, or one long thirteenday period.
2. Infants who suffered multiple separations had more pronounced,
longer-term effects than those separated only once. They were
reluctant to leave the mother to explore, and succumbed to
violent temper tantrums if the mother moved away.
3. Twelve months later, infants separated from their mothers for
either one or two six-day periods were compared with control
infants that had remained continuously with their mothers.
4. The Separated infants explored less and played less.
5. Separated infants also exhibited measurable physiological
changes in sleep patterns and heart rates.
6. Hormones like cortisol, produced by the body in response to
physical and psychosocial stress, were secreted at higher levels as
infants mobilized bodily resources to cope with the impending
challenges of an “orphaned” situation.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
Chapter 17: “Secure from What?” or “Secure from Whom?”
Anything but Blank Slates (Infants Prefer Facial Characteristics)
1. Infants don’t process random stimuli but seek out and fixate on
specific patterns, like the components of a human face. They
prefer curves, like cheeks or eyebrows, not straight lines, and
prefer strong contrasts of light and dark, like pupils surrounded by
the whites of eyes.
2. Newborns preferentially seek out faces with humanlike
configurations: two eyes, a nose, and a mouth.
3. And they distinguish symmetrical “pretty” faces and look at such
faces longer than at lopsided or grotesque ones.
Animal and Human Predators
1. Identifying mother is a critical first step to attachment, but
attachment for what purpose?
2. To avoid predators: possibly hyenas, and most likely big cats--tigers and leopards, jaguars and mountain lions.
3. AND to diminish the threat from unrelated males, predators from
the same species.
4. Children are intentionally targeted by stepparents, marauders
from other groups, and even by competing mothers.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
5. The possibility of infanticide selected for maternal
counterstrategies to forestall male aggression against infants
(mothers leaving their group; mating with multiple males)
6. And it may also have favored fathers inclined to defend their
progeny.
Rethinking “Fear of Strangers
1. Prior to five or six months of age, infants smile indiscriminately at
almost anyone.
2. After six months of age, however, infants begin to respond quite
differently to unfamiliar people.
3. Infant pulse rate rises; he or she may begin to cry.
4. Strangers strike toddlers as especially fearsome if they are
encountered in a strange place, especially if they are tall, male,
bearded.
Innate vs. Learned Fears
1. For hunter-gatherers, snakes and predators are not hazards to be
taken lightly.
2. Oddly, though, infants don’t have an innate fear of cats---big or
small.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
3. Snakes, though, do have a peculiar salience. All primates fixate on
them, take special notice.
4. Yet typically, infants first must learn to be frightened by snakes by
watching other group members react to them. Once learned
though, snake phobias prove particularly resistant.
5. Strange humans (especially adult males) are another story.
6. No one teaches babies to fear strangers. Their panic derives from
a built-in prejudice so deep it persists in spite of every
reassurance the parent offers.
Chapter 18: Empowering the Embryo
Embryonic Decisions (Red-Eyed Tree Frogs of Costa Rica)
1. Karen Warkentin, a graduate student at the University of Texas,
noticed that eggs laid by red-eyed tree frogs at her study site in
Costa Rica took anywhere from five to thirteen days to hatch. She
began to wonder if there might be a reason.
2. She experimentally introduced a snake onto the leafy refuge of
five-day-old eggs.
3. The nearly mature eggs respond to snake attack by jolting
themselves into hatching prematurely, rupturing surrounding
membranes and sliding off the leaf into the pond below.
Parrot snake attacks red-eyed tree frog egg clutch
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
4. Among other amphibians, predator-induced hatching is played
out in reverse.
5. Some salamander larvae slow down hatching if they sense the
presence of predatory gangs of flatworms. The larger the
salamanders are when they hatch, the better endowed they are
to escape being eaten.
Parent-Offspring Conflict
1. Among viviparous and suckling creatures like mammals--developing embryos whose mothers bear and then nurse live
young---immature can aspire to more control over when they are
born and how long they are nurtured.
2. They may also negotiate how much of the mother’s resources
they will be allocated.
3. To imagine embryos and sucklings as active agents this way is a
new way of thinking about gestation and lactation.
4. In the early 1970s, Trivers began to empower immature life
phases by talking about infants as active agents whose behaviors
could affect their own fates. This was a revolutionary perspective.
5. In the past, “parents are classically assumed to allocate
investment in their young in such a way as to maximize the
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
number surviving, while offspring are implicitly assumed to be
passive vessels into which parents pour the appropriate care.
6. Hamilton’s theory of inclusive fitness preadapted Trivers to
understand parent-offspring conflict.
7. An infant is related to itself 100% but shares only half of its genes
by common descent with its mother, and 50% with her
subsequent offspring, if full siblings; more like 25%, however, if
they have different fathers. The mother will be equally related to
all her offspring. Taking all this into account, conflict as well as a
large measure of cooperation is an expected feature of their
relations.
8. Parent and offspring are expected to disagree over how long the
period of parental investment should last, over the amount of
parental investment that should be given, and over the altruistic
and egoistic tendencies of the offspring as these tendencies affect
other relatives.
Tantrums
1. Weaning conflicts epitomized for Trivers the disagreement over
how much and for how long a mother should provision her
offspring.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
2. Just after birth, when suckling is essential for her infant’s
survival, a mother and baby are likely to be of one opinion. No
conflict early on.
3. As the infant becomes increasingly independent of the mother,
however, the burden for initiating contact with the nipple
shifts; the infant is more motivated to suckle than the mother
is to provide additional nourishment.
4. Because the infant is smaller and less experienced than its
parent, and its parent is in control of the resources at issue,
this competitive disadvantage forces the offspring to resort to
psychological tactics.
5. Tantrums are the most dramatic manifestation of these tactics.
6. Though they appear to be spontaneous outbursts, Trivers
believed tantrums could be quite calculated.
Maternal-Fetal Contracts (David Haig)
1. Haig is likely to describe genes as social---members of a team,
participants in a “parliament of genes”---rather than as purely
selfish.
2. Haig was one of a handful of pioneers in the new field of “genetic
imprinting”, the still poorly understood process by which the
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
same gene is expressed differently depending upon which parent
it comes from.
3. This special class of genes could “remember” whether they came
from the mother or father, and act accordingly to promote either
maternal or paternal interests.
4. These 50 or so genes are either activated or silenced depending
on whether they are maternally or paternally imprinted.
5. Many of these imprinted genes involve growth, perhaps especially
growth in utero.
6. David Haig: Maternal-Fetal Conflict in Human Pregnancy (10:37
mins.)
Mice
7. In animals like mice where females are inseminated by successive
males, paternally imprinted genes would have no “compunction”
against extracting as many resources as possible from the mother.
8. They must be countered by maternally imprinted genes coding for
thriftier development.
9. Untrammeled expression of paternally imprinted genes produced
giant babies, 130% of normal size at birth.
10. Fetuses whose growth factors were monopolized by maternal
instructions were dwarfed down to 60% of normal size.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
The Fetus’s Supply Line
1. The placenta synthesizes large quantities of a hormone called
chorionic gonadotropin, and releases pregnancy-maintaining
hormones into the mother’s bloodstream.
2. After 12 weeks, the fetus is in a strong position to command the
mother’s body to carry on with the pregnancy.
3. In some mammals like mice, bats, armadillos, monkeys, and apes,
the placenta has evolved so as to tap directly into the mother’s
bloodstream.
4. As a result, the mother is unable to constrict the vessels supplying
the embryo, and she cannot regulate the flow of nutrients to the
placenta without starving her own tissues.
5. Thus does the fetus gain considerable control over its own
provisioning.
6. Diagram of a Human Placenta
Maternal-Fetal Negotiations over Time of Birth, etc.
Pregnancy-Onset Diabetes
7. Prior to birth, hormones such as human placental lactogen,
produced by the placenta, increase nutrients like glucose in the
mother’s bloodstream.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
8. To drown out such hormonal propaganda, the mother is forced to
issue even stronger instructions of her own, work orders calling
for more insulin.
9. Haig speculates that there are maternally imprinted genes that
evolved to counter fetal greed.
10. If there is a genetic deletion of the maternal countermand,
there should be serious repercussions.
11. If the mother’s body fails to counter the fetal command on cue,
diabetes could result as an unfortunate by-product of the fetus’s
call for sugar-rich blood.
Chapter 19: Why Be Adorable?
Sibling Rivalry in Birds (American Coots and Bald Eagles)
1. Consider the contrast between eagles and coots, both of which are
“brood reducers”.
2. In the case of eagles,
a. Mothers lay eggs sequentially and hatching is staggered.
b. Parents never intervene as older chicks peck younger ones to
death.
c. Older chicks benefit the most.
d. Parents benefit as well because if the first egg is a “dud”, there
is a second chance.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
e.The losers are the last-hatched eagle chicks---eaglets.
3. Coot chicks are born spectacularly different than their parents.
a. The front part of their bodies are covered with orange bristles,
and the eyes and tip of the red beak are surrounded by brilliant
papillae.
b. The have nearly bald pates that shine a bright vermilion.
c. Among the coot chicks, fancy neonatal plumage changes
gradually over the space of three weeks, into gray adult
uniform.
d. The American coot routinely lays more eggs than the number
of young the two parents can successfully rear.
e. Their eggs hatch sequentially.
f. However, instead of allowing older chicks to kill younger ones,
g. They opt instead to equalize the odds.
h. Coot parents compensate for the competitive weakness of
later-borns by preferentially feeding them.
i. One third to one half of coot chicks starve before fledging.
j. By favoring the fanciest, parents make sure of feeding the
youngest.
Runaway Selection for Infantile Traits
1. Like sexual selection, “parental choice” has the potential to spark
“runaway selection”.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
2. If parents prefer fancy chicks, those parents who preferred them
are selected for.
3. Their surviving offspring would be disproportionately fancy, and
also grow up to be parents who both prefer and produce
appropriately fancy chicks.
4. Selection is simultaneously favoring chicks with the trait and
parents who possess preferences for it.
Natal Attractions in Primates (Dusky Leaf Monkeys)
1. Some primates are also born in fancy dress.
2. Dusky leaf monkeys give birth to orange-gold babies.
3. They have eyes rimmed by large, chalk-white circles.
4. They live high in the canopy of Malaysian forests with their
obscure, dusky, gray parents.
5. What possible survival advantage could outweigh the
disadvantage of being so visible to hawks, eagles, and other
enemies.
6. Could it be that infant primates born impractically ornate evolved
this way so as to attract more care from mothers?
7. Since they are born one at a time, there is no sibling competition.
Why Be a Flamboyant Baby?
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
7. Given how unconditional the “love” of mother monkeys and apes
typically is, what possible selection pressure to be “flamboyant”
could outweigh evident costs to baby monkeys of evolving
conspicuous natal coats?
8. The solution to this mystery lies in widening our field of vision to
encompass other females, not just the genetic mother.
9. The flamboyant natal dress in primates evolved as a natal
attraction, screaming “New Baby” to all benevolent alloparents in
the vicinity.
Do Humans Have Natal Coats?
1. At birth, all Caucasian babies have blue eyes, while the eyes of
African babies are almost colorless.
2. !Kung newborns, Mongolians, and the Native American
descendants of Mongolians often have clusters of dark pigment
at the base of their newborn spines.
3. Otherwise, the human infant’s color scheme is some blend of its
parents’.
Chapter 20: How to Be “An Infant Worth Rearing”
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
1. Unlike other primates, humans have a conscious capacity to
assess outcomes--a. to predict what costs a particular infant might impose on the
survival of an older sibling, or on family resources or
harmony;
b. to predict how a father or stepfather might behave;
c. to know ahead of time that the baby’s grandmother is about
to die and that there will be no one to help.
Factors Affecting Maternal Assessment
1. Some maternal likes and dislikes have an innate component.
2. Certain kinds of cries given by premature infants seem to be
universally disturbing,
3. while rounded heads and plump features are universally
appealing.
4. The sight of a defective newborn is profoundly disturbing,
5. and low-birth-weight babies are distressing.
Janet Mann’s Twin Study
1. Psychologist Janet Mann is one of the few researchers to look at
parental preferences.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
2. She undertook a longitudinal study of fourteen twins born at
extremely low birth weights.
3. Eight months after the mothers brought the twins home from the
hospital, all seven mothers were directing more attention to the
healthier twin of the pair
Effects of Baby’s Signals on Survival (The Masai of Kenya)
1. Psychiatrist Marten DeVries set out to study temperament
among Masai pastoralists in Kenya.
2. He arrived at the height of a ten-year drought.
3. Children and infants are the first in the population to starve in a
case like this one, where the majority of children were already
malnourished.
4. During this particular famine, infant mortality rose to almost 50%.
5. Amazingly, only one of the six infants with difficult, “fussy”
temperaments had died;
6. Five of the seven with “easy” temperaments had died.
7. Under stress from famine, it was easier for the mother to neglect
an undemanding baby.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
Birth by Stages
1. In modern Western societies, infants are regarded as fully human
the moment they are born, tagged, blood-tested, foot-printed,
granted citizenship and legal rights.
2. Mothers are encouraged to bond with their infant almost
immediately and regarded as strange if they do not.
3. More typically (86% of societies in one cross-cultural study), full
human identity is postponed till after some specific postpartum
milestone or rite of passage in which the baby is publicly
acknowledged, given a name, receives a soul.
4. In the majority of cultures, full rights as a group member are
postponed till after inspection and acceptance of the baby by
parents or alloparents who have committed to rear it.
5. In parts of Africa, South America, and in the Pacific Islands,
babies born with teeth, multiple births, or breech births can be
viewed as “ill omens” that prejudice parental acceptance of the
baby.
6. Almost all infanticide in traditional societies occurs right after
birth, and is conceptually identical to late-stage abortion.
7. Neonaticide is favored over abortion simply because infanticide is
safer for the mother.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
8. In no other primate do mothers appear to distinguish between a
new baby and a new baby that will be kept.
9. Everywhere, one trait parents pay close attention to is how
plump the baby is.
Chapter 21: A Matter of Fat
Introduction
Why are Human Babies so Big and Fat?
1. Adipose tissue of a full-term human fetus accounts for 16% of its
weight at birth.
2. This is proportionally four to eight times more fat than is found in
a baby monkey.
3. It would appear that human babies are particularly fat,
presumably because they need fat for something. But what?
Insulation for Naked Neonates
1. Polish anthropologist Boguslaw Pawlowski proposed that fat
provided insulation to protect babies from nighttime cold in a
species that had recently moved to the savanna and slept
“naked” and “on the ground”.
2. But why didn’t hominids solve the problem behaviorally by
huddling at night to stay warm or construct sleeping nests.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
Insurance Policies
1. Secondly, it has also been suggested that a larder of stored fat
could represent an insurance policy.
2. If a new mother were indisposed, her infant might have to wait
for her to recover, or if she died, wait for a lactating allomother
to come along and adopt him.
3. If baby fat is insurance against emergencies, other primates
would also have benefited from putting on a blubbery life vest.
Food for Thought
1. Neonatal fat provides a stockpile, or larder, critical for the
development of fast-growing, lipid-guzzling human brains.
2. Brain tissue is very expensive to produce and maintain.
3. According to anthropologist Leslie Aiello of University College
London, the demands of the brain account for more than 50% of
the total basal metabolic rate of a baby.
4. The newborn’s brain is only a quarter of what it soon will be.
5. Hence, big-brained hominids needed extra fat to grow on.
6. Birth weight is the single best predictor of infant survival.
Advertisement for Myself
1. In spite of their long, nine-month gestations, human infants are
born at an earlier phase of development than other primates,
Altricial.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
2. Why should the baby stockpile fat prior to its treacherous trip
through a bipedal mother’s narrow pelvic canal?
3. Near term the fetus builds up a thick layer of fat between the
shoulder blades and lays down fat around the arms and on pudgy
hands.
4. The mother is not responsible for the buildup; the fetus is.
5. As David Haig points out, once placental supply lines are laid
down, the mother no longer controls the flow of nutrients to her
fetus.
6. According to this hypothesis, fat babies are not only more viable,
but fat advertises what a good bet this baby is to survive, be
healthy, and enjoy full neurological development.
7. Neonatal fat becomes the equivalent of a coot’s fancy natal
costume, adipose advertising in place of colorful signals of
neonativity.
8. The erotic appeal and sheer deliciousness of a baby’s soft, plump
flesh may be viewed as the product of countervailing selection on
infants, to compensate for Mother Nature’s discriminating
human mothers.
9.
Roly Poly by Hank Williams (2:15 mins.)
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
Chapter 22: Of Human Bondage
1. “Bonding” is the modern version of the old ethological process of
imprinting---instinctive attachment of newborns.
2. Ethologist Robert Hinde convinced Bowlby that there might be
“sensitive periods” for learning, but that nothing so mechanistic
as “imprinting” was likely to evolve in a primate.
3. “Bonding” posited a rapid process whereby mothers form an
emotional attachment to infants in the hours right after birth.
4. Should a mother otherwise committed to caregiving miss the
first few hours or days, there are no measurable ill effects--provided someone else keeps the infant warm and safe in the
interim.
Mothers and Allomothers
1. What did Bowlby actually say? He said that primate and human
infants
a. are born immobile and vulnerable
b. respond very poorly to being left alone or to being made to
feel insecure
c. have a nearly insatiable desire to be held and to bask in the
sense that they are loved
d. These needs are enormous, and largely non-negotiable.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
2. What are the implications of this for their mothers?
3. Female primates have always been dual-career mothers, forced
to compromise between maternal and infant needs.
4. It is not a matter of “motherhood versus vocation”.
5. Rather, the question are:
a. Under what circumstances can a mother safely afford to
delegate care to allomothers?
b. How can allomothers be motivated to care?
6. Extensive data on people like the Aka and the Efé, show that
infants from birth are passed among multiple caregivers with
whom they become very familiar and quite at ease.
7. However, there is the practical observation that it is very difficult
to get people to look after other people’s children.
8. Does attachment theory “attach” the lives of mothers? Not
necessarily, but for mothers who care about their infants’ wellbeing it often comes to the same thing.
9. The majority of hunter-gatherer societies are characterized by
a. close mother-infant proximity for at least the first several
years.
b. Care of infants by fathers is unusual, and care by male
alloparents rarer still.
10. But this is not carved in stone.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
11. In infant-sharing species,
a. infants grow faster, and
b. mothers produce more surviving infants in a lifetime.
c. Shared vigilance helps reduce infant mortality.
d. Mothers not burdened by infants forage more efficiently
e. and their infants cultivate wide social networks
12. Human infants need mothers and allomothers to keep them
warm, safe, mobile, stimulated, clean, fed, hygienically hydrated,
and most important, to communicate tenderly and responsively
their commitment to go on caring.
Shortage of Alloparents
1. There are a greater number of children in daycare than ever
before in human history.
2. The burgeoning demand for good daycare far outstrips
availability.
3. Most children in daycare survive and develop normally.
The Importance of Behaving Like Committed Kin
1. The majority of mothers in postindustrial countries use some
form of daycare.
2. From a newborn’s point of view, mothers are rarely as close or
consistently available as the infant desires.
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Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
Chapter 23: Alternate Paths of Development
Blaming Mothers for Sociopaths
1. The idea of blaming the behavior of a grown-up on insecure
attachment to his mother has only entered our culture since
Freud, and especially since Bowlby.
2. Bowlby noticed that “sociopaths” were disproportionately drawn
from the portion of the population that had been “avoidantly
attached” to their mothers.
3. He assumed that their behavior was due to a disturbance in their
internalized working model of the world that made it hard for
them to learn to trust others.
The Nurture Assumption
1. Bowlby was apparently not aware that there is no one speciestypical, one-size-fits-all pattern of development.
2. Individuals differ
a. in innate temperament, e.g., whether they are shy or
extroverted.
b. in appearance, endurance, in what foods they can digest,
c. in susceptibility to diseases, both physical and mental, and
d. a myriad other attributes known to be influence by genes.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
3. Individuals also experience different parental effects, e.g.,
mother’s or father’s social status, locale, or kin networks affect
an offspring’s prospects.
Surviving Detachment
1. It never occurred to the first generation of attachment theorists
that high proportions of insecurely attached infants (30 to 80% in
some populations) could be anything other than aberrations
produced by unnatural rearing conditions in the modern world.
2. But the fact is, no one knows what proportion of insecurely
attached infants existed during the most relevant periods of
human prehistory, when the genetic makeup of our ancestors
was being forged.
The Post-Bowlby Era of Attachment Theory
1. Patricia Draper was an anthropology grad student at Harvard
when she first went, in 1968, to the field to study the !Kung San.
2. At first she focused on how mother-infant relations were
influenced by ecology and social structure. Gradually her interest
expanded to include emotional development.
3. Bowlby had assumed that drastic departures from the
circumstances of the EEA (such as separation from mother in
infancy) would lead to aberrant adjustments.
4. Draper was not so sure.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
5. Draper and her then husband, biological anthropologist and
geneticist Henry Harpending, hypothesized different
developmental trajectories that would be more or less adaptive
for a child, depending on circumstances.
6. Draper and Harpending hypothesized that children would mature
at different rates and develop different styles of coping with the
social world, depending on whether they had learned to rely on
their parents or on peers.
Birth Order and Personalities
1. In the book Born to Rebel by Frank Sulloway, Sulloway was able
to show distinctive patterns in which:
a. firstborns were more likely to identify with and defend the
status quo,
b. while later-borns (those “born to rebel”) were more likely to
challenge the status quo and endorse revolutionary ideas.
c. Siblings internalized quite different working models about
how they expect the world to work.
2. A wanted son and an unwanted daughter might experience a
mother’s care very differently, as differently as if they had been
born to different species, or born in quite different habitats.
3. Yet somehow, some unwanted children do manage to survive,
albeit stunted to varying degrees, emotionally and physically.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
What Makes Us Humans?
1. Secure attachments early in life have long-lasting effects, not so
much on temperament or cognitive capacities as on degree of
empathy for others.
2. Countries like the U.S. pour money into prisons while investing
proportionally far less in early development programs designed
to convince infants and children that they belong to a community
that will treat them like kin.
3. These are the circumstances that signal a developing human
organism that it will be worthwhile to grow up caring about what
happens to others.
Chapter 24: devising Better Lullabies
Childhood Fears
1. A securely attached infant is an infant secure about his world in
general, present and future.
2. A secure infant is far more comfortable, even in his mother’s
absence, than an infant in doubt about his mother’s
commitment.
3. It is not turning an infant over to allomothers that has harmful
repercussions. It is failing to convince him or her that
abandonment is out of the question.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
The Sensual Responses Babies Produce
1. The responses by a lactating mother mammal to her baby’s
sucking long antedated sexual responsiveness to breast
stimulation in heterosexual (or any type of intimate) contacts.
2. The feeling women identify as sexual were originally maternal.
3. Erotic arousal in the mother during breast-feeding can be
correlated with increased milk ejection.
4. Maternity and sexuality are inseparable linked in ways that just
are not true for paternity and male erotic experience.
5. Sexual desire in men and other male primates evolved because
copulating with females increased the chances their sperm would
fertilize an egg.
6. Having eggs fertilized, however, is just one of the ways that
copulating serves a woman’s reproductive ends.
7. Others include the various roles men play, both positive and
negative, in keeping her baby safe and fed.
8. Maternity is inextricably intertwined with sexual sensations, and
it is an infant’s business, through grunts and coos, touches and
smells, to make the most of Mother Nature’s reward system,
which conditions a woman to make this infant a top priority.
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Notes for ANTH 342: Human Behavior and Evolution; by Brad R. Huber
Mother Nature: Maternal Instincts and How They Shape the Human Species
Part Three: An Infant’s-Eye View
What Babies Seek
1. Sociobiologists accept some degree of maternal ambivalence as
inevitable.
2. This insight, together with an awareness of the underlying
sources of maternal ambivalence, helps make sense of some of
the very odd things that mothers say and sing to children.
3. Around the world, lullabies intended to calm babies often seem
to fall short of the mark.
4. Lurking predators, strange males, or the prospect of maternal
ambivalence are precisely the threats little primates ought to fear
most deeply.
5. What infants yearn for is the reassurance that they will never lose
their caretaker’s love, that no matter what, she (or he) will keep
them safe from any lurking hazard.
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