740 likes | 1.54k Views
What is Ethology?. “comparative animal behavior” Primary method of study is the observation and quantification of behavior in the field and lab. “ Human Ethology” ?. So, how does the “human” part change the field?.
E N D
What is Ethology? “comparative animal behavior” Primary method of study is the observation and quantification of behavior in the field and lab.
“Human Ethology” ? So, how does the “human” part change the field? Acknowledges unique biological attributes of the human species, how BOTH human culture and biology evolved to become inter-dependent
In A Word...What is the humanpart of ethology? Culture: dependence on tools, symbols, language and learning for survival… genetic and behavioral plasticity and capacity for immediate innovation (change)--environmental regulation
Like……here are some examples.. • beliefs about how babies should be born..changes the biological experience of birth..(labor duration) • socialization either favoring or discouraging aggression makes it harder or easier to be aggressive… • expectations and beliefs about food, the psychology of food, changes what we eat and why..affecting our health.. • Mead said:” We don’t eat food, we eat ideas about food”; • how and where we sleep, and what we think about a “good nights sleep” depends on our cultural beliefs… • What is it that actually happens when we “psyche ourselves up” or “hit that groove..” • Humans make decisions
Evolutionary Perspectives on… Human beings… Early bipedal hominines 3.5 million years ago, 390 cubic centimeters of brain to… Homo sapiens sapiens What does it mean to evoke evolutionary concepts into our understanding of humanity… 50-150,000 years ago..1500cc’s For the sake of the babies
800,000 150,000 400,000 Changing morphologies and Changing behavior over time 130,00 32,000
3mya 2mya1mya .5myaToday The Hominins ↓ Humans → → → → ↓ ↓ Homo sapiens sapiens Filling in the dots…..
A day in the life of a Pleistocene, early Homo baby, 800,000 years ago. Any Relevance to the western 2009 baby? Us? For the sake of the babies?…How?
Absolutement !We are a species that invented the phenomenon of “ideas” sometimes referred to as “memes” the culturally-based, functional analog to biologically-constituted “genes”. Nonetheless, ideas operate and are expressed in relationship to an ever-present, powerful, successful, paleolithic (Stone age) biology. Still, ideas (or memes) change faster than infant or maternal biology ..as ideas or memes..are made possible by…
The evolution of the human brain…increasing encephalization relative to body mass.. MODERN HUMAN MODERN CHIMPANZEE • increasing complex problem solving abilities involving regionalized tools and technologies, enhanced communication and interpretive social- skills, extended, bi-parental care in the context of more enduring male-female sexual relationships, symbolic behavior and belief systems
Stanley Kubrick “2001”: The perfect visual metaphor..for illustrating what anthropology tries to do From this To that • We try to fill in the dots between fossil ancestors, connecting hominine fossils with each other through time..and reconstructung the relationship between morphology (brain size, anatomical characteristics ….and social behavior…
The Indonesian “hobbit”….3.6 ft feet tall, 800 cc brain..late Homo erectus, up through 300,000 to 15-11,0000 BP years ago…overlapping modern forms…phyletic dwarphism isolated on ecologically attractive but competitive environment “Homo sapiens florisiensis” hunting large rats and Kokomo dragon
Brain Quality and Volume And the Rise of Human Culture -------------] Modern Human size Range ] ________]
defined “ethology.”.now working on defining what it means to do “human” ethology… leads to understanding relationship between biology and culture…(brain size and behavior) the background and features associated with human evolution.. what happened, why, what is different about us. .how did we do it? How do we know? What is the “human” evolutionary legacy? Tools of Human Ethological Research So, my friends….where were we…? in our warming up to think differently about contemporary human behavior..adding an additional framework..time depth..background, tools to understand….
David Barash: TheTortoise and The Hare (1987) “ …There would be little if any difficulty exchanging a Cro-Magnon and a modern infant, but great incongruity in making the same switch amongst adults of both cultures.”
And what else does culture do? Answer: (Lots) “Although the biology of human behavior is universal in historic time how humans perceive what the SHOULD do..or what is..ahhh “cool”….is socially constructed and subject to historical change.” (adopted from Sussman 1982)
Human Culture and Brain Size -------------] Modern Human size Range ] ________] Fire,shelters,systematic hunting, clothing, hand axes, flake tools, migrations Wood? stone choppers,unifacial flaked toolsl Language, burials,religion? integrated tools, agriculture, pottery, sedantism
How Did We Manage To Afford Such An Expensive Brain, Slow Developing Brain, Needy Brain, With A Relatively Larger Body Size and Reduce Birth Intervals at the same time? HUMMMM…HOW DID WE DO THIS
Increased size of foraging home ranges; Shifted to enormous breadth of food types with high protein omnivory coupled with production of tools to harvest and prepare; We cook, too! Food sharing in social context, division of labor , with non-relatives no less! Reduced mass of gut; Emancipation of sexual behavior from hormonal control.. Symbolic communication; non-verbal communication (mix) Birth to fat, really “cute” babies! Rise of alloparents..to become cooperative breeders! Make/Depend on Tools..(fake organs?) HOW?
Risks? Of a big brain… Still, the Risks: second trophoblastic invasion..(eclampsia, pre eclampsia result) as emerging embryo penetrates more deeply into womb for increased oxygen and nutrients Architecture of bipedal pelvis diminished outlet complicating labor and delivery; Cultural construction of birth and infant caregiving practices…far from ideal?
Risks of preeclampsia….defective implantation of the placenta…a couples disease… Disease of first pregnancy….10% of all human pregnancies…3 months after first implantation..in uterus (the zygote)..inefficient penetration of the placenta..leading to increased blood pressure..to get nutrients to fetus… The longer the father has exchanged fluids with the mother, therein exposing her to his antigens, the less likely the disease finds expression!
Hypertensive disorders of pregnancy.. preclampsia (edema) and eclampsia (convulsions) Caused by…..short periods of male-female cohabitation….40% of couples with less than 4 months of cohabitation; 25% amongst those with 5 to 8 months; 15% of those with 9-12 months; and 5% of those with more than 12 months
Why Humans? Human fetal brain requires 60% total maternal nutritional supplies in utero compared with 20% demand of maternal energy in utero amongst the other 4300 mammal species!!
Symbolic (verbal and non-verbal) capacity-language, self awareness, reflection, evaluation; awareness of death; Retention of breasts; Variable adult male parental investment; Technology (dependence on tools)..culture Mind readers..empathic, tolerant, understanding; Reduced gut mass, efficient digestion; On human unique nesses:
Bipedal, long labor, woman attended birth; birth of fattest babies Extreme Delayed maturity; Largest neo-cortex and relative to body size..tissue convolutions maximize axonal-dendritic connections and speed; Long child dependence, food sharing; Increased parental investment; Concealed ovulation, loss of estrous; Post reproductive senescence (life after menopause) Direct and indirect male care Energetically costly babies, BUT short intervals between births; On human unique nesses:
“Will the Real Pleistocene Family Please Stand Up?” (after Hrdy 2008) Environment of Evolutionary Adaptedness?? For the sake of the babies… what was a day like in the life of an 800,000 year old Homo? Shortened birth intervals explained by: Cooperative breeding (Hrdy 2008) ? Direct male care (Gettler in press) ?
Humans are geniuses at mutual understandings .. Caring about and imagining what others think, and what something means to the other.. Caring about the intentions (intentionality ) – Figuring out what others might do and what the self should do in relationship to others; Developing a “theory of mind “ The primacy of cooperation amongst early human beings ….living on the savannah.. Bipedal life on the savannah and in the forest required social planning
Relevance of Past Selective Pressures to Contemporary Behavior? Meet the “EEA” Meet the neighbors!
Really, A Central Question For the Class is: What Is Human Nature? (Or is it, really natures?)
What Aspects of Human Life Constitute a “Nature” ? • Emotional and Behavioral “tendencies” ? • How we sleep? Why we get fat? Fight? Select Food? Laugh? • Give birth? Satisfy Hunger? Own things? Want things? • Raise our babies (parent)? Protect our babies? Soothe (or not) our babies? • Stay healthy, trade health for other gains? • Look for, look good, and find a mate? Circumstances of having sex and being sexual? • Communication skills (interact successfully…conduct social business, appease, maintain group cohesiveness, reduce ambiguity, build unity? • Desire to discover? Learn? Explore? Feel? Empathize/ Control? Be “Happy” (a new concept)?
What determines the “nature’ of human nature? • genetic, familial, historical, cultural, physical, economic and environmental processes; • “Natures” may be extremely variable, flexible and diverse: sensitive to the social values, ideologies and overall cultural practices of the groups within which the behavior develops; • Culture plays a huge role….even that we think it important to know what our “natures” are…
Why does your answer to the question--what is human nature --matter?because “..the behavior of men is not independent of the theories of human behavior that men adopt” Leon Eisenberg “The Nature of Human Nature” pg 165 (1972)
How we define people..what you expect of them..i.e. define their natures..becomes a self-fulfilling prophecy • Evolution of the concept of mental retardation… • Middle ages..defined as insane..sent to prisons..treated like animals and so like raving maniacs they became.. • 17th Century….mentally retarded treated like children..juveniles, stripped of adult rights..and so like children they became..barely learn sentences… • 21st century USA..”mainstreaming”..full educational experiences..life experiences…opportunities..and so like independent functioning citizens the …mentally slow become
Why Important? “Pessimism about man serves to maintain the status quo”. Leon Eisenberg pg. 167 1997 “The Nature of Human Nature”
A question... Are human emotions the closest we will ever get to understanding our genes, i.e. what you feel, rather than what you act on, or necessarily do?
Human Ethology: Uses Diverse “Lines of Evidence” • Comparative (what kind) • Cross-cultural (other societies) • Cross species (other species) • Inter-individual (intra-sexual) differences; • Developmental (the life cycle--from blast cyst-embryo-fetus-neonate-infant-child-adolescent-adult) • Evolutionary/Phylogenetic origins/function
Human Etholgists Ask Five Fundamental Questions: • What does the behavior look like? Ahh! observation! • What causes the behavior to occur? • proximate cause vs. ultimate causes • How does the behavior develop? • Ontogeny: individual life cycle • How, why and when did the behavior evolve? • Behavioral Phylogeny--how is it adaptive? • How does the behavior function?
Assumptions Underlying Human Ethology • successful behaviors evolve; • behavior mediates between the organism’s genes and environment for maintenance --all leading to reproduction; • But what is being “selected” or “favored” genetically is often difficult to say… • is the “trait” “epiphenomenon” (that is, noise) or a real, biological, evolved “adaptation”?
We assume that: a relationship exists between the degree to which the environment (social or physical) can change genetic expression--and behavior..and the degree of complexity of the animals’s nervous system …(brain size) the larger the neo-cortex--the more the animal depends on learning..greater plasticity in behavior
Human Brain Expansion Over Time • Species with larger brains can alter their behavior quickly to changing environmental demands
Assumptions con’t • Organisms use energy resources differently at different stages of the life cycle..behavior changes with age: growth, maintenance and reproduction (life history theory). • Cultural behavior (learning) changes the degree, form, and expression of genetically based human behaviors…long chain between genes and behavior…
Another Assumption Culture changes much faster than does human biology.(no dependence on genes)…only dependent on human creativity..insight, ideas…
Memes Vs Genes ? Dawkins (The Selfish Gene) “memes” refer to non-organic behaviors, innovations, or ideas passed on quickly from one person to another, one generation to another which while not based on biology nonetheless have both biological and cultural significance.
Fundamental Concept In Ethology Evolution: change in the genetic structures and general behaviors of organisms through time…achieving adaptation (reproductive success)
Concepts/Questions basic to ethology (human or otherwise): “analogous” traits vs. “homologus”traits Examples; human smile? hand grasp/shake? Reproductive strategies? Facial expressions, living in groups? Sleep? Birthing?