Human Ethology As Anthropology: a holistic
understanding
(to understand we use four lines of evidence):
(1) Developmental
Cross-cultural
(range of
variability, role of
social valaues)
(socialization)
human
Sleep
abuse and
neglect
One third of our lives spent
doing it!
(2)
Evolutionary
Origins,
Function,
Reconstruction
(3) Cross-species
Sleep
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What is it? What Does It Look Like?
Do other animals sleep?
How does it function? Why did it evolve?
What happens when we sleep?
Measurement?
How does it change with age and with each
culture?
What contributions does culture make to how
we think about it, interpret and evaluate
sleep? How does sleep develop? Infant sleep
vs. adult sleep?
Human Ethology Lines of
Evidence
What causes sleep?
How does it develop?
How does it function?
How did it evolve?
What is sleep?
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A state of (1) sustained immobility or
quiescence in a (2) characteristic posture
accompanied by (3) reduced responsivity to
external stimuli;
Immobility need not be absolute as dolphins,
seals and whales may float or swim while
asleep…most sleep with eyes closed but not
all;
Cattle may sleep with eyes open..horses and
elephants sleep while standing…
Recognizing sleep: behavioral
criteria
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Behavioral inactivity;
A characteristic sleep posture
Decreased responsiveness to
stimulation
A rapid return to waking with moderate
stimulation
Why Do We Sleep?
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Proximate
Explanation:
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Because we begin to
“feel” tired..melatonin 
Need to consolidate
energy and experiences;
Need to avoid predators;
Need to restore body
cells and promote protein
anabolism;
Maintain hormonal
secretions, immune
function
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Ultimate Explanation
» sustains our
ability to
reproduce
successfully, by
maintaining good
health
What happens when falling
asleep--transition to Stage 1
Body temperature drops;
 Slow rolling eye movements;
 Alpha rhythm ((8-13 cycles per second)
 Heart rate slows;
 Relatively low voltage, mixed
frequencies.(vertex sharp waves)
 Myoclonus jerk?
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Sensitive to external stimuli--dreamlike
thoughts
Circadian rhythm
Refers to circa=approximately and
dias=day
What’s the Endocrine System?
A collection of glands that secrete hormones in
order to regulate functions within the body.
Environmental cues: activity and rest =growth,
maintenance, hormonal fluctuations.too
Earths rotation--light-dark cycle, on 24hour circadian system. Activity-nonactivity (circadian rhythms) can be
further subdivided up into smaller time
activity-rest units,called, ultradian cycles
 As wakefulness (alert), stage 1 sleep,
stage 2, stage 3 and stage 4 (Non-Rem)
and Rem (rapid eye movement sleep),
also called active of paradoxical sleep.
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About life, students….
Its about circles..i.e. cycles…all the way
down…we live inside of circular space..
» cycles within cycles within cycles…
» as in life cycle..sleep cycles, menstrual
cycles, hormonal cycles..time
cycles..midnight
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(when and where morning and night are
simultaneously one, a beginning and an end at the
same instant.. Where beginning and ending is the
same, is it Friday or Saturday
Light cues
24 hours
Active vs. Rest
What is “sleep architecture”
(Awake/sleep)
drowsy, stage 1,stage 2, stage 3.
Stage 4, REM, drowsy
Awake/sleep
Studying The Physiology and Nighttime
Behavior of Breastfeeding Human
Mother-Infant Pairs
Conversing with data
across discipline
cultures:
polysomnography
Why was the
first ever
physiological
study of
mothers and
infants cosleeping
completed by a
biological
anthropologist
?
Polysomnography (tracings)
Sometimes babies sleep in mother-baby sleep laboratories
Sleep Laboratory Lounge
Nighttime Sleep Studied From a New Bio-cultural
Perspective
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Solitary infant turns
prone-face down;
Educated nurse
wraps up baby;
Clinically depressed
teen;
Breastfeeding moms
Increased sensitivity
Environmental cues (zeitgebers) and selective
pressures determine how and when animals
sleep
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Dolphins, whales, porpoises need brain
awake to monitor breathing and to
detect danger. Experience
“unihemispheric” synchronization--one
half of brain exhibits synchronous EEG,
the other dysynchronous--that is, one
half of the brain is awake the other,
asleep.
Reptile Species
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Crocodiles an alligators rest-activity brain
waves are temperature dependent…
Lizards and snakes--eye tissues reflect some
REM-like movement but it remains
questionable;
Turtles and tortoises--somewhat likely as EEG
spikes correlate with arousal from sleep in
some species
Reptiles? Crocodiles, Alligators, Lizards, Snakes,
Turtles and Tortoises
Meet behavioral criteria
 Different electroencephalographic (EEG)
patterns during behavioral sleep
 High amplitude spike potential --but,
recall, reptiles lack human neocortex
that generates slow- wave sleep..(but is
present in mammals in certain
subcortical areas)
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Sleep Position? Locale?
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Bats and sloths sleep upside down, hanging
by their feet;
Belly, side, haunches, or back-…all
positions?..depending on anatomy and
environmental pressures,
“Type” of predator can determine sleep locale
cave, crevice, tree, nest, or whether animals
sleep together for protection in herds
(giraffe,antelope, wildebeast, many primates)
What Co-sleeping Looks Like
Koala
Maori, New Zealand
napping desert Aborigine
recliner co-sleeping (unsafe)
Diversity of Co-sleeping
(requires taxonomic distinctions)
Co-bedding twins
(within sensory range)
partial, mixed
bedsharing with Dad
Oh, But let’s not forget the Dads.
Ventral-Ventral mother-infant contact: is
not an example of unsafe sleep
Courtesy of Dr. Helen Ball
…Solitary Sleep
What is REM sleep?
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Rapid eye movement..during a sleep period
(eyes dart from right to left) stimulates occular
muscles;
Called “active sleep” or “paradoxical sleep”;
Respiration is irregular, heart rate is generally
faster, blood pressure is higher…brain waves
fast and shorter;
Dreaming occurs;
REM (not just a rock group)
REM contributes (makes possible)
metabolic homeostasis;
 Deprivation experiments on rats reveal:
» Deprivation of REM leads to eating
more, but losing weight, loss of control
of body temperature
» Death ensued in 30 days
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Function of REM?
Exercise brain cells (neurons) for
memory consolidation, cognition
 Oxygenate and distribute nutrients to
body organs and muscles;
 Metabolic homeostasis: temperature,
cortisol, prolactin, melatonin release,
human growth hormone?
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During REM, atonia occurs
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During REM
»
Inhibitory neurons release glycine on
surface of motoneurons;
Creates a form of electrical polarization,
preventing the discharge of large muscle
sets involved in locomotion, prevents them
from discharging;
» Prevents acting out dreams..this is called
atonia
»
Across Cultures the meaning and function of dreams vary:
Dreams
Real acts performed elsewhere in time and spacedeja vu- ?…considered channels of
communication; shamans learn how to control
events and disease; in some cultures both
spaces..”real an imaginary” are distinct but both
considered..real..:
Dreams….
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A dream takes place in a subjective space,
different from the space of walking life;
The relationship between these two spaces is
not the same from one culture to another…
For Ojibwa Indians..dreams are another way
of acting in “life space”..having visited a spot
in one’s dream…
BUT..no culture confuses dreams with waking
reality, or fails to make a distinction..
Culturally
specific..
Content?
Direct?
Indirect?
Creativity:
Dr.Jeckll and
Mr. Hyde
(Robert
Louis
Stevenson)
Samuel
Taylor
Cooleridge:
Fell asleep in
1797-dreamed 200
lines of one
of his finest
poems:
Kubla Khan
Dreams
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Dreams discussed by Greek
philosophers…Pythagoras, Plato,
Aristotle..sleeping in certain temples provided
access to dreams..special cures ..special
knowledge..
Aristotle: attributed dreams to “residual
sensory impressions”..to a persons
past..presented without controlling emotional
senses..in present..but not access to power
What kind of genetic trait
underlies human sleep?
Polygenetic--gene complexes?
 Facultative?
 Obligative?
 How “labile” is our need for sleep?
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Daily Sleep Quotas of Various
Mammalian Species (in Hours)
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Opossum (18)
Bat (19)
Mole (8.5)
Baboon (9.5)
Humans (8?)
Rabbit (8)
Hamster (14)
Rat (13)
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Giraffe (2)
Horse (3)
Dog (10)
Seal (6)
Dolphin (10)
Cat (12)
Squirrel (16)
*70% of all sleep is
NREM..Rem varies from 30 min.
for Giraffe to 5 hours for opossum
Polyphasic Species
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Baboons-3 -4 naps?
Rabbits-evenly
distributed. light/dark
Rodents: Gerbil,
guinea pig (all day,
short sleep periods);
Cat (domestic) 12/15
cats nocturnal--2 sleep
periods during night,
most sleep periods
during day;
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Dogs--polyphasic--with
emphasis of sleep at
night;
Horses --polyphasic--316 sleep bouts per day;
Goats 0-6 sleep
episodes per 12 hour
period (polyphasic);
Thompson’s gazelle-mostly night--3-6 during
day;
Most vulnerable mammals?
Wake up frequently, must remain
vigilant..to predation
Or must be alert to other
environmental dangers (dolphins
and sharp rocks and reefs)
Relevance of Napping Across
Species
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Is napping one
variant of
“polyphasic sleep”-an evolutionary
human relic?
What are the
different trade-offs
related to survivalfor different sleep
lengths at different
times?
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How do naps and
sleep patterns vary
according to:
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Activity patterns
(diurnal, nocturnal,
split)?
Carnivores vs
herbivores
Habitats: secure,
insecure, terrestrial,
aquatic, avian?
What Kind of Sleep Pattern
Do Humans Exhibit?
Monophasic?
Biphasic
Polyphasic?
The concept of…the “Sleep debt”
“The brain keeps an exact
accounting of how much sleep it is
owed!”
William Dement: “The Promise of
Sleep”
Sleep Disorders
Restless leg syndrome--about 10%
population:
 Insomnia--not sleeping;
 Parasomnias--not staying asleep for
desired length
 Introduce “die model” (western
societies)..a problem?
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Primary or Secondary Enuresis
(bedwetting)
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Surprisingly common:
25% of four year olds,
10% of 8 year olds, 1%
18 year olds;
Not a disease but a
symptom..delayed
maturity, insecurities;
rule out: diabetes,
cerebral palsy, chronic
urinary tract infections;
sleep apneas
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occurs in any stage of
sleep;
Behavior modification
(75% cured)
Imipramine and /or
demopressin acetate
(DDAVP)--as a nasal
spray;
patience and tolerance
Sleep disorders
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Apneas (without breadth) can be divided into
two types
» obstructive and central apneas
» Obstructive apneas afflict 50 million
Americans, 20% of which have serious
disorders--increases blood pressure and
increases coronary build-up--can induce
heart attacks..
–snoring heavily is one symptom, but
daytime sleepiness is the single most
important clue
Reducing apneas----
“CPAP”
continuous positive airway
pressure
Sleep Disorders
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Somnambulism…sleepwalking
» 40% of children will have an episode,
peaking at between 11-12 years of
age;
Can be induced if arouse children during NREM;
» associated with complete amnesia,
» Occurs within 2 hours of falling asleep..
EEG..reveals both waking and sleep signals.
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Considered benign.
Where is the “culture”--in sleep?
on what do we sleep,in what room?
 why we sleep, where we sleep, with
whom we sleep;
 When we sleep, what clothing we sleep
in (if anything) .. what we do before we
sleep (rituals--prayers? cleaning,
grooming,making love, reading,
speaking with someone)
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Napping and Culture:
“Although sleep may be judged a necessary part of sleep,
napping has often been considered deviant and an
unwanted form of sleep, indicative of laziness, senility,
Immaturity, and irresponsibility”. Broughton and Dinges 1989
The “siesta” is a universal
behavior that is de-valued with
industrialization in some western
countries..associated with
indolence or laziness..i.e. ”never
get caught napping” ?
Development of Sleep; General
trends
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Infancy--18 hours a day of sleep; fall right into
REM sleep--little day-night
consolidation/demarcation..Breast feeding vs
Bottle, cosleeping vs. solitary?
Toddlers; naps until about 3 years of age-experiencing 11-14 hours of sleep..stage 4
sleep within ten minutes
Slow wave sleep for about an hour--then
mixed movement/arousals/ 7-10 REM cycles,
about 30-35 % of total sleep..70% non-REM
Birds eye view of developmental changes
through the life cycle (Ontogeny)
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From infantile polyphasic pattern---toward
increasing consolidation of night sleep with
multiple daytime naps…to a single daytime
nap (3-4 years of age) to the emergence of
the more common monophasic adult sleep
pattern……to
Adolescent 8-11 hours--with more Stage 3-4
sleep to..young adult…to….
Older adult--less stage 3-4, less total sleep,
more naps/and polyphasic pattern (back to
infancy)
Does the human fetus sleep?
6 to 7 month old fetus develops
REM/Non-Rem sleep precursors;
 By end of 8th month, patterns
established; mimick post-natal
quiescence and activity;
 Active sleep is developmental precursor
to REM--Quiet Sleep in newborns
represents precursors to Stages 1,2 3,4
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Human evolutionary origins of
sleep? (Phylogeny)
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Consider life style (the paleo-ecology) of
Australopithecines 3-5 million years ago)
» Lived in a predator rich habitat (social
carnivores);
» fossil evidence of hominids being
heavily preyed on by large cats
(leopards and saber-tooth cat);
»
Hominids were slow, weak, without claws,
sharp teeth: What did they have going for
them?
The Hominid Dilemma?
Bipedal, free hands, clever brains;
 Innovative , using and making tools
 Living and communicating in social
groups, perform “social roles’
 dependent on learning;
 expensive, slow developing, immature
babies, unable to run or cling to mom
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Where Did They Sleep 3-5 million to
300,000 Years Ago
Trees? with grasping
adaptations..building nests,,sleeping in
nests like present chimpanzees...
 Caves?
 Roosting sites? Cliffs?
 What changed things--when could
hominids come to the ground to sleep
safely?
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Felididae: Sabertooth Cats
Felids…(Megantereon)across
three continents
Fire, changed things!
(In evidence by 800,000 years
ago) with Homo erectus
Fire could be used as a weapon
against large cats and other
predators..sleep could be
prolonged..and , on the ground!