Evolutionary Psychology Flashcards
What is Jean Baptise Lamarck’s concept of evolution?
Believed that organisms tend to progress towards higher lifeforms and features and characteristics organisms are inherited
Animals must struggle to survive -> secrete fluid that enlarges organs involved in struggle
What is the struggle for existence?
Favorable variations tend to be preserved, and unfavorable ones tend to die out. When this process is repeated generation after generation, the end result is the formation of new adaptations.
What is Catastrophism? (Léopold Chrétien Frédérick Dagobert Cuvier)
Proposed that species are extinguished periodically by sudden catastrophes to be replaced by another species
What is the theory of natural selection?
3 factors:
Variation - organism vary across attributes
Inheritance - some of attributes are inherited and reliably passed down over generations
Selection via differential reproduction success - heritable attributes that allow organism to reproduce more offspring than others (the bottom line of end all of selection)
What is classical fitness?
Odds of an organism with a certain attribute surviving till reproduction
What is sexual selection?
Adaptation that arose as a consequence of successful mating
How did sexual selection arose?
Attributes that appear to serve no survival function or even be costly to survival would not have favored by natural selection but apparently persisted in several organisms
What is intra-sexual competition?
Individual faces competition for mates amongst others of same sex. During intra-sexual competition, the competition that occurs pertains to who possesses traits and characteristics superior to other of the same sex (e.g., strength, wealth, etc). These characteristics allows individuals to outcompete other individual of same sexes, to gain access to mates directly, or indirectly, such as by controlling resource or territory.
What is inter-sexual competition?
A tug-of-war between members of different sexes, in terms of mate preferences. To achieve reproductive success, individuals need to meets the demand of the opposite sex. Those who are unable to do so fail to reproduce because they do not possess certain qualities (e.g. being generous with gifts) to meet that demand. In every species, there will be a particular sex, who are more picky in their choice of mates (as later outline in parental investment theory).
What are the other driver of evolutionary change?
Random changes (generic drift) can occur as
Mutation: random changes in genetic makeup of a population
Founder effect: small portion of population establishes a new colony and the founders of new colony are not genetically representative of the original population
Genetic Bottlenecks: Happens when a Catastrophe occurs and a few members survive with a certain gene and there will be an overpopulation of that certain gene
Natural and sexual selection is not…
Is not intentional - selection merely acts on variations that exist based on recurrent advantages for survival and reproduction that the characteristics confers; cannot anticipate future demands
Natural and sexual selection is
gradual, some rapid, over generations - may depend of the complexity of the organism e.g viruses evolve rapidly vs mammals
How does the theory of natural selection applies to behaviour?
There is a clear association between the existence of physical characteristics and the existence of behaviors
- Behaviour require support from anatomic and biomechanical infrastructure for enactment.
- Species can be bred for certain behavioral characteristics using principle of selection e.g Dog
What is Mendelian Genetics?
Qualities of parents are not blended but are passed on in distinct packages called GENES
- Parents are born with genes not acquired by experience
Gene: smallest discrete unit that is inherited by offspring intact without being broken up or blended
Genotypes: entire collections of genes within an individual
- Discards Lamark’s theory of inheritance of acquired characteristics and blending theory of inheritance
What is fixed action patterns?
stereotypical behavioral sequences an animal follows after being triggered by a well-defined stimulus
What is inclusive fitness?
= Classical Fitness + (Effect of the Organism’s Action on the Fitness of Genetic Relatives × Genetic Relatedness)
Why was classical fitness too narrow?
If the bottom line of reproduction is the survival of the gene, natural selection ought to favor characteristics that support the survival of the gene, regardless of whether the organism produces offspring itself.
Survival of the gene can be ensured by aiding genetic relatives.
What is the Hamilton Rule?
Understanding altruism could have evolved when it imposed cost onto self
Benefits to genetic relatives must have been greater than the cost to self
rB>C
r – proportion of shared genes
B – fitness benefits in terms of how many offspring are produced
C – fitness cost to self
What is Group selection?
natural selection acts at the level of the group instead of at the level of the individual or gene
Why is group selection is now disfavored?
Altruistic organisms that sacrifice themselves for the benefit of the group are less likely to survive. Selfish organisms are more likely to survive and reproduce.
Selections at the genetic level work against selection at the group level
What is George C Williams’ criteria for adaptation?
Reliability - Does mechanism regularly develop in most or all members of the species across all normal environments?
Efficiency - Does mechanism solve a particular adaptive problem well and effectively
Economy - Does the mechanism solve the adaptive problem without extorting huge cost from organism?
What is Robert Triver’s theory of reciprocal altruism?
the condition where altruism – the act of helping unrelated others while incurring a cost to self – could have evolved.
Altruistic helping may be beneficial when there is potential for repayment for the altruistic act in the future
What is Robert Triver’s Parental Investment theory?
Sex that invests more in its offspring will be more selective when choosing a mate
- Less-investing sex will have intra-sexual competition for access to mates
What is Robert Triver’s Parent-Offsprings Conflict theory?
- Resources invested in offspring are resources not available elsewhere (e.g., other offspring)
- Parents look to maximize fitness benefits from parental resources invested, while offspring look to maximize parental resources gained from parents
What is the sociobiology controversy?
Edward O. Wilson published a highly controversial book, Sociobiology: The New Synthesis, which attempted to integrate various batches of evolutionary and biological science,
- Claimed the integrated principles can be applied to all organisms.
- Claimed that Sociobiology will “cannibalize psychology”
- Forgo many important psychological principles (e.g., learning, reasoning, culture) that form the foundation of psychology and focus largely on behaviors
- Evidence being largely from non-human sources
- Imply that humans possess mechanisms with the goal of maximizing their inclusive fitness, that is, maximizing their gene representation in subsequent generations.
Is human behavior genetically determined?
NO.
Genetic determinism is the doctrine that argues that behaviour is controlled exclusively by genes, with little or no role for environmental influence (Nature)
Clarification 1:
Human behaviour cannot occur without: 1. Evolved adaptations and 2. Environmental input that triggers the development and activation of these adaptations
Environment influences is apparent at all stages of evolutionary processes: environment as selective pressure, developmental inputs and triggers of psychological mechanism
- AKA behaviours caused by genes without input or influence from environment are simply false
- Evolutionary Psychology rejects any claims of genetic determinism
If it’s evolutionary, we cannot change it right?
NIEN
-Evolved characteristics and behaviour require triggers to activate
- Some changes are easier than others
- The extent to which change can happen depends on the extent to which plasticity is favoured by natural selection - adaptive plasticity
- Knowledge of evolved social psychological adaptations + social inputs -> give us power to change social behaviour
- Evolved characteristics are not necessarily unchanging, static, or permanent
Adaptations that organisms posses today are optimally designed over generations of selection!
NO
Many factors of our adaptations is far from optimal
- Evolutionary time lags where change in environment > time required for adaptation - “stone age brain in modern environment”
E.g. strong taste preference for fat and sugar was for past environment due to scarce resources, now lead to type 2 diabetes, clogged arteries (we have outpaced natural selection)
Costs of adaptations
- All adaptations carry a cost in some forms
- Adaptations are only beneficial in so far that fitness benefits outweigh the cost
E.g. if we wanted to be safe driving, we should all just drive extremely slow -> obv the cost of it is too high
- High cost will prevent people from solving other adaptive problems
Adaptations are often far from optimal due to design constraints
We evolved to be this way hence; this is the right way to be and the best way to be!
NO
Naturalistic Fallacy
- The belief that what is “natural” - how nature is - is therefore “good” and how things should be.
- e.g., “Warfare must be allowed because human violence is instinctive.”
Moralistic Fallacy
- The belief that what is “good” is, therefore, how nature is. The belief is that if something is “bad,” it is not “how nature intended it.”
- e.g., “Warfare is destructive and tragic, and so it is not of human nature.”
What is adaption?
Inherited and reliably developing characteristics that came into existence thru natural selection as they helped solve problems of survival or reproduction better than alternative designs
What are the characteristics of adaption?
- Inheritance by genetic transmission
- Most characteristics are coded not by a single gene but by a complex aggregation of many genes - Develop reliably to solve adaptive problems.
- Emerge at appropriate stages of development, not necessarily at birth
- In a reasonably intact form - Some adaptations are species-typical; others are sex or in subsets of the population.
- Depending on whether the subgroup faces the recurrent adaptive problem over their evolutionary history - Adaptations are functional
- Adaptions are shaped by natural selection
- Each adaptation has unique environment of evolutionary adaptedness (EEA)
- selective forces or adaptive problems responsible for shaping the adaptation over the organism’s evolutionary history - Each adaptation has a period of evolution
- the time span natural selection takes to shape the adaptions to its functional form
What does functional mean in context of adaptions?
how the adaptation solves adaptive problems – the precise solution
What is design features of an adaptation
the components and processes of adaptive solutions that contribute to solving the adaptive problem
What is the criteria when determine for adaptions?
Precise - components of adaptation are design to achieve a particular outcome that solves adaptive problems
Efficient - solves the adaptive problem well
Economic - cost effective
Reliable - Performs dependably in the specific contexts it is designed to operate in
How are adaptions shaped by natural selection?
- Each adaptation first emerges as a mutation – an error in the genetic coding - resulting in a characteristic that deviates from its previous form.
- Mutated characteristics that harm the organisms are removed from the gene pool (sometimes by chance) as they hinder survival and reproduction.
- Beneficial mutations are retained and passed down as organisms achieve differential reproductive success.
What is a by-product?
Characteristics that do not solve adaptive problems and do not have functional design; are “carried along” with characteristics that do have functional design because they happen to be coupled with those adaptations.
What is noise?
- Random effects are produced by forces such as chance mutations, sudden and unprecedented changes in the environment, or chance effects during development.
- It can be harmful or neutral
What is the evolved psychological mechanism?
is a set of psychological processes with the following properties:
- Exist because they solved a recurrent problem of survival or reproduction over our evolutionary history.
- Their core component (i.e., design features) were shaped in a way they coordinated to overcome specific obstacles to survival or reproduction. - An evolved psychological mechanism is designed to take in only a narrow slice of information as inputs.
- The spectrum of input the psychological mechanisms sensitive to is relevant for the detection of adaptive problems that are recurring over the EEA – or in modern environments that mimic these inputs - The input of an evolved psychological mechanism tells an organism the particular adaptive problem it is facing.
- Perception can happen consciously or unconsciously. - The input of an evolved psychological mechanism is transformed through an algorithmic decision rule or procedure into outputs.
- The decision rules are sets of procedures —“if, then” statements—for guiding an organism down one response or another. - The output of an evolved psychological mechanism can be a physiological activity, information about other psychological mechanisms, or manifest behavior.
- Outputs of psychological mechanisms can act as inputs to other psychological mechanisms or as manifest behaviors - The output of an evolved psychological mechanism is directed toward the solution to a specific adaptive problem.
- The output of the mechanism may not always be successful, but on average, it tends to solve adaptive problems.
Are Evolved Psychological Mechanisms domain specific or domain general?
- Adaptations are solutions that need to be specific to addressing the problem faced
- Generalized solutions, even if they work, they are unreliable and imprecise because they are not designed for a specific problem
- Every solution, including adaptations, can fail. Errors are more likely to arise from solutions not designed for the problem.
– When errors occur, they present themselves as a threat to survival and reproduction
– Organisms evolved to process mechanisms specifically designed for correcting errors (e.g., vomiting)
Do Humans Possess a Complex Array of Evolved Psychology Mechanisms?
- Humans face a large number of adaptive problems over our evolutionary history.
- Each adaptive problem requires a specific psychological solution
- Consequently, we possess just as many evolved psychological mechanisms to address the multitude of adaptive problems.
Why does humans have high level of behvaioural flexibility?
- Behaviors are not rigid “instinct.”
Without environmental stimuli acting as triggers (IF), there will be no behavioral response (THEN) - Some mechanisms feed input to another mechanism as outputs
- The huge number of mechanisms humans possess allows us to generate a huge range of behavioral responses.
- Response can be altered by changing the input, by changing the environment, or by the operation of a psychological mechanism producing an input as output.
Explain the proximate operations of an evolved learning mechanism by socialization and cultural influences?
- Learning requires an environmental input surrounding the individual to generate an output mimicking
- Learning, socialization, and endorsement of culture require an evolved psychological mechanism to attend to environmental cues to generate functional, learned, or culturally-influenced behaviors
What is General Evolutionary Theory?
describes the evolutionary principle that natural selection is the core engine of the evolutionary process by which adaptations emerge.
What is a middle-level theories?
When the core principle of natural selection is applied to specific domains of life.
What is specific evolutionary hypothesis
Using Middle-level theories, researchers can then generate specific hypotheses about the operation of evolved psychological mechanisms.
What ways can we generate hypothesis?
- Top Down (Theory Drive)
- Developing Hypotheses from Existing Theory - Bottoms-Up (Observation Driven)
- Developing Hypotheses by Observing Behavioral, Physiological, or Psychological Phenomenon
What is the social brain hypothesis (Dunbar, 1998)
Primate seems to have comparatively larger brain sizes than other organisms.
- Primate, including humans, are known to be social-living organisms
- Social interactions require neurological infrastructure to support – brain size correlates with group size.
- Humans likely lived in approximately 150 individuals
How can we identify adaptive problems?
1.Existing knowledge about the ancestral environment
2. Applying middle-level theories to the EEA to identify who is most likely to face adaptive problems
3. Must-solve vs. Beneficial-to-solve adaptive problems
4. Threats vs. Opportunities
5. Magnitude of impact and Frequency of encounter
What is task analysis?
Specify the (a) relevant end state—the solution to the adaptive problem— and proceed by (b) detailing the specific design feature of the psychological mechanism capable of producing that end state.
What does cost benefit analysis allow for?
nuanced prediction regarding the operation of the evolved psychological mechanism – across different cultural contexts, individuals, and sex.
-Context may vary the fitness cost and benefit of manifested output. For example, when facing contaminated food:
What is the hunting hypothesis?
Global cooling a few million years ago marked a dramatic decrease in plant-based food sources, making animal hunting the more attractive food source
What is the physiological and paleontological evidence for the hunting hypothesis?
Physiological evidence:
1. humans digestive system designed for processing meat in small intestine vs fiber in colon
- Humans unable to produce Vit A & B12, found in abundance in meat despite being critical to human bodily function
Palentological evidence:
1. No show in wear and tear in teeth associated with fibrous plant diet in human fossil
2. Cut marks on collection of bones indicate early butchering attempts
How does food drive human evolution?
Hunting hypothesis, provisioning hypothesis, the show off hypothesis, gathering hypothesis
What is the provisioning hypothesis?
Meat from big gain hunting is highly economical and concentrated food resource -> transport meat calories more cost effective than lower-caloric food over long distances -> allow for heavy investment of resources to children
What does the provisioning hypothesis explain?
- Strong male coalition -> large game hunting requires coordinated action btw males
- Reciprocal altruism and social exchange -> Share excess food -> incur social debt
- Sexual division of labor - men biologically + physiologically better for hunting + women care for child -> would trade gathering food for meat
- Emergence of stone tools
What is the show-off hypothesis?
Women are more likely to offer benefits to men who can provide gifts of food particularly in times of shortage - offer sex, care for their kids, siding with them for conflict
Benefit for men: gain social status
What is the gathering hypothesis?
A competing hypothesis to the hunting hypothesis, which speculates the emergence of tools was not driven by hunting but by digging and gathering plants - making gathering efficient and economical
-> how much women spend on gathering food depends on how much men bring back from hunting to compensate for a poor provider
What are some issues with the gathering hypothesis?
Does not explain: strong male coalition, sexual division of labor, human’s ability to live in an environment with poor plantation, social exchange btw. men and women, humanity’s digestive anatomy seem designed to process meat rather than plants primary
How has food driven human evolution in term of the sex differences in abilities?
Men - superior navigational ability, abstract and euclidean direction orientation (aids navigation thru unfamiliar terrain during hunting), superior mental rotation - facilitate tool and projectile use during hunting
Women - superior recognition and recall of spatial configuration and location of objects, landmark-based direction orientation, superior object perception and perceptual memory - facilitate identification of gatherable food
What explains the preference for spices for solving the adaptive problem of food contamination?
Antimicrobial hypothesis
- spices are produced as chemicals by planting to deter organisms and pathogens from attacking them -> Spices (Garlic, onion, allspice, oregano) used to kill foodborne bacteria -> climates where food spoils more quickly tend to favor a spicier cuisine -> cuisine as an adaptive cultural practice
Explain how humans evolved to have food aversion to avoid toxins and contaminated food.
Neophobia - aversion to unfamiliar food
Humans generally avoid bitterness, which usually indicates toxins
Aversion functions for acidic food -> appreciate - ripe or rotting fruits that contained acids that inhibit harmful microbes
- fermentation by lactic acid bacteria better food digestibility, hence increase food calories
- in lack of nutrients -> food rotted by yeast or lactic acid bacteria likely represented a valuable food source that could increase the chances of survival
Why do humans like alcohol consumption?
We have adaptive preference for ripe fruit - alcoholism may be a byproduct
As fruits were mainstay of primate diet -> ethanol plumes cue ripeness -> ripe fruit averages about 0.9% ethanol and up to 4.5% at overripe
What is the behavioral immune system hypothesis (disease avoidance hypothesis)?
Pathogens cannot be detected directly but indirectly via effect on food and infected organisms: smell, look symptoms -> disgust is an affective output that motivates avoidance and withdrawal of offending stimuli
What are some predictions that can be made from the BIS hypothesis?
- Disgust should be most strongly evoked by disease-carrying substances
- Given that all humans face adaptive problem of avoiding diseases, the operation of BIS should be universal - cross-cultural studies suggest that disgust is universally evoked by spoilt food and feces
- Disgust should trigger physiological response associated with immune responses e.g. increase body temp.
- People should show a strong memory for potential sources of contamination
- Sex differences in disgust sensitivity - women more likely to be disgusted than men
What is the Savanna hypothesis?
Humans face adaptive problem of surviving hostile elements of nature; natural selection would favor preference of living environment that provide abundance of food and water and facilitates avoidance of environmental hazard
How do humans select their habitat?
- Selection - first encounter -> affective response are invoked to influence the decision to stay or live
- Information gathering - environment is explored for risk and benefit
- Exploitation - decision is made to stay and exploit available resources or leave. cost-benefit trades are weighted
What is the Savanna principle?
Humans tend to face great difficulty processing inputs that did not exist in ancestral environments, often generating maladaptive output as a response
e.g. individuals live in high pop. density but with low levels of socialization with friends tend to report lower well-being than individuals living in rural environments
What is the sequence of fear responses?
Freezing, Fleeing/Flight, Fighting, Submission/Appeasement, Fright and Faint
What is the difference between freezing and fright
Freezing: inhibiting movement - muscle is tense - active activation + Cognitive component: you can access the situation
Fright - you feel faint - your muscle is loose + You don’t have the cognitive ability to assess the scenario
What are the sex difference in fear?
Sex difference in fear explained by the sex difference in the likelihood of encounter and cost of encounter
- men are more likely to survive threat encounters than women; hence, women are more likely to harbor fear
- fear interferes with risk-taking in men to obtain status, resources, and mating opportunities
What adaptions has humans evolved to deal with environmental hazards?
Human possess information-process adaptions for over-estimating environmental danger to facilitate avoidance of danger
- bias towards perceiving sounds of object approaching from behind
- Decent illusion - overestimation of distance when viewing from top to bottom (vs. bottom to top)
What is the theory of senescence?
The deterioration of all bodily mechanisms as we grow older
- Telomere, region of genetic coding at the protective end of the chromosome, shortens with each cell replication -> Result in the gradual deterioration of functional characteristics in living organisms
other external factors could be uv radiation, stress ect
What is the pleiotropic theory of senescence?
Certain genes may promote fitness enhancing effects early in life but cause negative effects later.
- For example, testosterone facilitates status enhancing behavior amongst men but increases the risk of prostate cancer later in life.
- Natural selection weakly affects the gene because the benefit it provides early in life outweighs the cost it imposes on the organism later in life
What two hypotheses can explain why humans commit suicide?
Evolved suicide adaptation hypothesis + maladaptive by-product hypothesis
- both can be partially correct
What is the evolved suicide adaptation hypothesis?
suicide will most likely to occur when an individual has dramatically reduced ability to contribute to their inclusive fitness -> replication of an individual’s genes would have a better chance w/o the suicidal individual
- Evidence suggest suicidal ideation +ve correlates with fitness-reducing concerns: damaged health, financial problems, relational an sexual failure, burden to family
What is maladaptive by-product hypothesis?
Fitness-reducing events are usually temporary; there are always future opportunities to enhance fitness -> suicidal idealization may be an adaptive “call for help” -> accidental death as a result is a by-product
How does the evolved suicide adaptation hypothesis explain the sex differences in rate and patterning of actual suicides?
More men than woman fail in hetro mating-> these failures occur during peak years of mate competition (15-35)
Men are more likely than women to suffer from infectious diseases, cardiovascular diseases and liver dieseases in older age -> become burden to family
How is existential terror a unique adaptive problem to humans?
Like animals, humans want to survive however human ability for abstract thoughts make possible the awareness of one’s inevitable end -> potential for existential terror can seriously interfere with goal-directed behavior and perhaps survival itself unless effectively managed
What do we deal with existential terror (terror management theory)
solution: cultural worldviews which are:
1. a conceived theory of reality that gives life meaning, purpose and significance
2. standard by which human behavior can be assessed and have value
3. a hope of literal or symbolic immortality
- Literal immortality: beliefs one will continue to exist beyond bodily death
- symbolic immortality - belief that one is part of an entity greater than oneself, which will persist beyond one’s death
How does parental investment and sexual selection affect mating preferences?
Sex that invest more in offspring will be more discriminating or selective about mating and the sex that invest less in offspring will be more competitive for sexual access to high investing sex.
Childbearing and its ability are invaluable reproductive resources and those who bear those resources do not give them to anyone
How is mate preference an evolved psychological mechanism?
Mate preferences evolved to address adaptive problems associated with reproduction
Traits, tendencies, and characteristics that promote fitness are preferred, those impost cost are avoided
What are the adaptive problems faced by women that shape women’s long-term mate preference?
- A mate who is able to invest
- A mate who is willing to invest
- A mate who is able to physically protect her and children
- A mate who will show good parenting skill
- Mate who is compatible
- Mate who is healthy
How do women can tell if a mate is able to invest?
Look at current resources, if not for future resources - preference for characteristics indicative of resource acquiring ability
Qualities like
- Intelligence and creativity
- Ambition and industriousness
- Size, strength and athletic ability
- Social status
- Somewhat older men
Why do women look for men with high social status?
Humans live in groups with clearly defined social hierarchy; resources typically trickle from top to bottom with those of higher status having most control
Why do women like somewhat older men?
Older men have more time to build alliances, skills and mastery of environment + Wealth & status tend to +ve correlate with age for men
BUT not too old
- old men more likely to be infertile + more pregnancy problems
- Increase risk of genetic abnormalities
- Less likely to live longer -> fewer years of investment
Why do women seek for mate who is willing to invest?
Men typically seek sexual variety and may channel their resources toward another woman instead + tend to withhold resources during paternal uncertainty -> need to find guy willing to invest resources to them
How do women tell if a mate is willing to invest into her?
Looks for:
- Dependability and stability - signal that resources will be provided consistently over time
- expression of love and commitment -> intention to commit all their resources to one woman and their offspring
- willingness to invest in children -> sign for paternal qualities and women appear to able to detect if men like infants
Why women seek for mate that is able to physically protect her and children?
Women sometimes face domination by other larger, stronger males, which leads to injury and sexual domination
so strong and physically powerful male with high aesthetic ability signal ability to offer protection
Why do women select mate who is compatible?
Successful long-term mating requires sustained cooperative alliances over time -> similarity leads to emotional bonding, cooperation, communication, mating happiness, lower risk of breaking up and possibly increased offspring survival
What do women look for in a mate’s compatibility?
Homogamy - preferences for someone who shares similar values, political orientation, worldviews, and individuals differences + positive assortative mating -> choose mates similar to themselves in phenotype characteristics than would be expected by chance
Why do females choose a mate who is healthy?
Mating with unhealthy mate imposes costs on women such as
- unhealthy mates c/n deliver food, protection and parental support efficiently
- premature death cut off resources
- potentially carry disease and poor genes
How do women select a mate who is healthy?
Preference for symmetrical face and body
- signal ability to withstand environmental and genetic stressors
Preference for masculine features
- testosterone is an immunosuppressant; only healthy males can absorb the “cost of producing high levels of testosterone”.
- signal dominance and physical prowess
With the lower reproductive cost and usually being the sex that controls the allocation of resources, why would men want to commit to a single mate for the long term?
- Reduced intrasexual competition from men who failed intersexual competition
- Men who are willing to commit will be seen as more desirable by women
- Increased quality of mate
- Women who typically desire lasting commitment are also typically in the best position to ask for commitment
- Reduced paternal uncertainty through exclusive sexual access
- Increased survival odds of offspring with prolonged parental investment of both parents or related kins
- Increased reproductive success of offspring from paternal investment
- Increase social status
- Access to partner’s resources and status
- Increase lifespan
Why is dependability and stability in a man important to women?
Men who lack dependability and emotional stability -> erratically and inflict heavy emotional and other costs on their mates
-Tend to be self-centered and monopolies shared resources
- Become more dependent on women
- More verbally and physically abuse
- Divert own time and resources while taking partner’s
What are the adaptive problems face by men that developed their long term mate preferences?
- Selecting a mate who has high reproductive value and fertility
- Parental uncertainty
- Mate who has good genes
- Mate who is compatible
- Mate who aid mutual survival
What is reproductive value?
Number of offspring given the age and sex, an individual is likely to have in the future
What is fertility?
Actual reproductive performance measured by the number of viable offspring produced
What is considered attractive to males?
Long, high quality hair, skin quality, feminine feature, facial symmetry, facial averagesness, long legs relative to torso, lumbar curvature, lower waist to hip ration than the local average (ard 0.7)
Why do men like women with high lumbar curvature?
Lumbar curvature -> explains why men like big butts lmao
- Centre of gravity starts to shift upwards and forward when female is pregnant -> so curvature of the spine -> minimize risk of torque -> ensure child can survive -> so like women with high lumbar curvature (aka therefore have like big butts)
Why is paternal uncertainty an adaptive problem faced by human men?
As women bear offspring -> know that child is theirs and males of other species have cues of estrus (heat) -> during heat period can pioritize sexual intercourse and defend mate from other males -> HOWEVER for men, signal is not directly available
Men also c/n guard mate 24/7 given other adaptive problems -> cannot assure offspring is his -> also dw to invest resources to other men’s offspring
What are the evolved preference that men have to deal with paternal uncertainty?
Chastity
- Chastity and sexual permissiveness signals potential future infidelity aka women is a virgin
- Females also call out other females for not practicing chastity -> to decrease their mate value + assure men that offspring is theirs (dual function of inter and intra sexual competition)
Sexual fidelity
- Faithfulness, commitment, and loyal characteristics are highly desirable to men
- Women can signal fidelity with mate defensive behaviours
What are the context effects on women long term mating strategies?
Personal resource, Other attractive women, Personal mate value
How does personal resources affect a women’s mating strategy?
Women holding more personal resources (ie wealth and career prospects) place even more emphasis on good financial prospects and characteristics associated with ability to acquire resources
How does the presence of other attractive women affect a women’s long term mating strategy?
Copying is relatively energy efficient means of generating adaptive solutions -> getting information from others who have likely achieved reproductive success is an invaluable resource
AKA if another attractive women finds a man attractive -> assumption that man possesses attractive qualities that she doesn’t know/see
How do personal mate value affect a women’s mating strategy?
Women with more attractive qualities are highly desirable to men -> have more options and are chooiser
More attractive women will prefer more attractive men
What is the benefit of short-term mating for men?
Increased number of offspring fathered
What is the costs of short-term mating for men?
STD, Reputational cost, lower survival odds of offspring due to lack of parental investment, aggression from jealous rival or long term mate, aggression from woman’s male kin (father, brother), retaliatory kin (female partner cheats back)
What are the evidence for men’s short term mating preferences?
Sexual fantasies and sex drives - more fantasies more about having sex with strangers, switching and having multiple partner
Extramarital affairs
Prostitution & Hookup
Testicle Size
- human male tend to have larger testicles compared to other male species
- The size of larger testicle size is due to sperm competition -> to beat other males you just need to produce more sperm
Variation in sperm insemination
- Sperm count increases with increasing amt time since the last sexual intercourse with long term mate
- Assuming males cannot be with his mate due to other adaptive problems -> short window for other men to have affair with mate -> solution is to have higher sperm count to crowd out rivals sperm
Time Elapsed before Seeking Intercourse
- Men have greater likelihood of consenting to sexual intercourse after little time has elapsed - willingness to engage in sex across all conditions (lower standard)
What are the adaptive problems associated with men’s short term mating?
Problem of partner number/variety, problem of identifying which women are fertile, problem of avoiding commitment,
How does men deal with the problem of partner number in short term mating?
- Desire for variety of women
- Relaxation of standards
- Minimize time lapse before seeking sex
- Preferring promiscuous women with higher sex drive
- Sensitivity to cues of sexual exploitation - male find women who are more exploitable as more attractive for a short term mate
- Sexual regret - negative affect in response to missed opportunities to motivate future attempts
How do male deal with the problem of identifying which women are fertile in short term mating?
Preferring fertile women over women with high reproductive value
Preferring promiscuous women with higher sex drive - signal to higher likelihood to gaining sexual access
How do male deal with the problem of avoiding commitment in short term mating?
Males want to reduce commitment (Don’t want to divert his resources) -> the solution is sexual regret which comes in play and is used for men to not have sex with the “wrong” women
What is the evidence for women’s short term mating?
Male mate preference
Women orgasm
Timing of affairs
What are the 5 hypothesis about the adaptive benefits to women of short term mating?
Resource Hypothesis, Genetic benefit hypothesis, Mate switching hypothesis, Short term for long term goals hypothesis, mate manipulation hypothesis
What is the resource hypothesis? (Short term mating for women)
Paternity confusion hypothesis: Women engage in short term mating for resources -> each men willing to invest some investment in case child is theirs
Protection hypothesis: primary man not there to protect -> gain protection with another
Status enhancement hypothesis: elevate social status to gain access to higher social circle by temporary liaison with high status man
What is the genetic benefit hypothesis? (Short term mating for women)
Enhance fertility -> if mate is infertile -> use short term mate to provide back up
Sexy son hypothesis -> mate with attractive man -> produce sexy son that have better chances
Enhance genetic diversity for child
What is mate switching hypothesis? (Short term mating for women)
Women mate stop bring resources, abuse or decline in value -> use short term mate to get rid of long term mate or trading up to higher quality mate
What is the short term for long term goals hypothesis? (Short term mating for women)
Use short term mate to evaluate and assess prospective long term mate
- avoids man that is in long term r/s
- avoid man that is promiscuous
What is mate manipulation hypothesis? (Short term mating for women)
If mate in affair -> gain revenge for his infidelity and deter him for future infidelity OR increase mate’s commitment if he see evidence of other men being interested in her
What are the cost of short term mating for women?
Reputation cost
Unwanted and unaffordable pregnancies
STDs
Resource withdrawal from long term mate
Higher odds of sibling conflict due to lower genetic relatedness
What are the context effects affecting short term mating?
Parental influence -> absence father, harsh family environment, harsh parenting and history of sexual abuse linked to preference for short term mating for both sexes
- no daughter guarding, life history theory
Life transition - causal sex is related to people’s development stages e.g. teenage experimenting + divorce, change in social status ect
Sex ratio -> change magnitude for inter and intra sexual competition
Individual differences -> mate value, traits ect
Why do women invest more than men in the care of their offspring?
Paternal Uncertainty & Mating opportunity cost
What is the mating opportunity cost hypothesis?
Males will invest in parenting if they less likely to incur mating opportunity costs – personal mate value, sex ratio, pop density
What can explain the sex differences in parenting adaptations?
As women are certain about maternity and father are not -> selection favor parental adaptions that differ from men
Primary caretaker hypothesis, Tend and befriend hypothesis, The baby effect
sex differentiated differences in parenting does not imply men do not take care and protect their offspring
What is the primary caretaker hypothesis?
Women have evolved adaptations that increase odds that their children will survive
e.g. women vs men show preference for photos with infants and view them longer + better at recognizing infant facial expressions
Why?
Attachment promotion hypothesis: women better at decoding facial expressions of infants to likely produce securely attached children
Fitness threat hypothesis: women should be sensitive to dangers that may be conveyed by -ve emotions
What is the tend and befriend hypothesis?
Tending: protecting children from dangerous threats by calming and quieting them down to avoid detection
Befriending: creating and maintaining social networks that offer a social cocoon of protection - women vs men likely to see friendship under stress
What is the baby effect?
Women take less risk in presence of an infant - balloon pumping test
What is parental care?
Preferential allocation of parental investment to one or more offspring
What shapes the evolved psychological mechanism for parental care?
Investment in offspring = not available for other offspring + own fitness –> natural selection shape parents to invest in offspring more likely to provide a reproductive return on investment
What are the inputs of the evolved psychological mechanism for parental care sensitive to?
Genetic relatedness of offspring to self, Ability for offspring to convert investments into reproductive success, inputs suggestive of an alternative use of investments instead of investment in offspring
How does genetic relatedness of offspring to self affect parental care?
Mothers are more likely to insist on infant’s resemblance to father to assuage parental uncertainty
Men are more receptive to baby faces that resemble them
Men will invest more resources to their genetic children + if children is current mate
What is the Cinderella effect?
Step parents less likely to report having parental feelings for stepchildren + parental discrimination to genetically unrelated children is a by-product of parental care
How does offspring’s ability to convert parental care into reproductive success affect parental care?
Healthy baby hypothesis
Age of the child
Trivers-Willard hypothesis
How does alternative use for investment available for parental investment affect parental care?
Time + energy for parental care = not available else where - Benefits of parental care > mating opportunity cost
Women’s age is related to infantcide (reproductive value), Women’s marital status is related to infantcide
What is the premise of conflict in the parent-child conflict?
Evolutionary conflict on interest
Child Pov: I want to maximise resources from parents
Parents Pov: giving fair allocation of resources yields maximum efficiency in fitness benefits
-> parents share only 50% of genes with child so imperfect genetic relatedness results in evolutionary conflict of interest
What is an evolutionary arms race?
when two organisms are each other adaptive problems - cycle of evolution and counter evolution adaptations
What are the areas of parent-child conflict?
In Untero, Sibling relations and offspring mating decision
What is altruism?
Behaviour or an act that a. incurs a costs to self in order to provide b. provide benefits to another person
Is Hamilton’s rule a theory?
No, it describes the selective pressure where natural selection will favor altruism
What are the implications of Hamilton’s rule?
Truly selfless characteristics cannot evolve
Nothing in inclusive fitness theory demand existence of adaption for kinship -> many species do not live with kins
Kinship mechanism favoured if cost of altruism CONSISTENTLY enhance the reproductive odds of genetic relatives
What are the universal aspects of kinship?
- Ego-centered kin terminology will be universal
- Critical distinctions along lines of sex -> how you treat your brother diff from sister
- Critical distinctions along generation -> r/s btw. parents and children is often asymmetrical
- Dimension of closeness linked to genetics
- Dimension of cooperation linked to genetics
- Elder members of extended kin wll encourage younger kin to be more cooperative and altruistic towards other kin (elder have higher genetic relatedness)
- One’s position within kin network - core component of self concept
- Universal ability to identify actual kin
- Use of kinship terms will be used to persuade and influence others with no actual kinship - e.g. frats
What are the empirical findings support theoretical implications of inclusive fitness theory?
Alarm calling in ground squirrels - predator confusion hypo, parental investment hypo, inclusive fitness hypo
Kin recognition - to provide aid, need to be able to recognize them –> recognize odor + facial resemblance - who to ally, who to exploit, who to avoid
Kin classification - genealogical distance, social rank, group membership
Genetic relatedness - emotional closeness + psychological grief
Living w/o kin sucks + living with kin enhance survival
Patterns of inheritance
What are the different types of kins?
Sibs vs Half Sibs, Grandparents and grandchildren, Aunts and uncles and cousins
All grandparents are related to their grandchildren by 0.25 -> why do we see some grandparents invest more in their grandchildren than others?
Double paternal uncertainty -> Grand father - Father, Father - Child (FaFa) vs Grandmothers and mothers 100% of their maternity
-> increased chance of genetic links broken = less likely grandparents would invest
What is the order of investment by grandparents?
Maternal Grandmother (MoMo) > Maternal Grandfather (MoFa) / Paternal Grandmother (FaMo) > Paternal Grandfather (FaFa)
Why do maternal grandfather (MoFa) invest more than Paternal grandmother (FaMo)?
Paternal grandmother -> likely have daughter, which she knows is 100% theirs -> investing in that daughter’s kids is more secure than investing in son’s children
VS Maternal grandfather has no better outlet for investment than in daughter’s children (investing in son’s children will be double paternity uncertainty for him)
What is the grandmother hypothesis?
Menopause -> evolutionary function for ceasing reproduction -> invest in children + grand kids -> increase inclusive fitness with declining reproductive value
What is the absent father hypothesis?
Men die young or men leave older mate for younger mate -> more beneficial for women to stop reproducing and invest in kids and grand kids
How does aunt and uncles invest despite being genetically related to children by 0.25 coefficient?
Sex effect - aunts invest more than uncles - men invest more resources into mating efforts than kin
Laterality effect - maternal aunts invest more than paternal aunts and maternal uncle than paternal uncles (parental uncertainty)
What is a single family?
A single parent or conjugal pair in which only one female reproduce
What is extended family?
Groups in which two or more relatives of the same sex may reproduce
Why are families rare? (only 3% of avian and minimalism species form families)
- Reproduction is delayed and sometimes directly suppressed
- Competition for resources such as food is concentrated rather than dispersed make life more difficult for both parents and offspring
=> Reproductive benefits of staying in family > cost of forgoing early reproduction
What are the 2 theories that explain how families evolved?
Ecological constraint model and familial beneficial model
What is the ecological constraint model?
Families emerge when there is a scarcity of reproductive vacancies that might be available to the sexually mature offspring
- Both cost of staying with family and the benefits of leaving are low
- Early production not possible owing to lack of reproductive vacancies
What is the familial beneficial model?
Families form because bounty of benefits they provide for offspring
Some benefits are:
- Enhanced ability to compete -> acquiring skills or greater size by staying home
- Enhanced survival → aid and protection from family
- Possibility of inheriting or sharing the family territory or resources as a result of staying at home
- Inclusive fitness benefits gained by being in a position to help and helped by genetic relatives while staying at home
What are the 3 premises Emlen’s theory of family formation?
- Families form when more offspring are produced than there are available reproductive vacancies to fill (ecological constraints)
- Families will form when offspring must wait for available reproductive vacancies until they are in a good position to compete for them
- Families will form when the benefits are large
What are the predictions that can be made using Emlen’s theory of family involving family dynamics of kinship and cooperation?
- Families will form when there is a shortage of reproductive vacancies but will break up when the vacancies become available
- Families that control many resources will be more stable and enduring than families that lack resources - inheritance
- Help with rearing the young will be more prevalent among families than among comparable groups lacking kin relatives
- When a breeder is lost because of death or departure, family members will get into conflict over who will fill the breeding vacancy
- The loss of an existing breeder and replacement by a breeder who is genetically unrelated to family members already present will increase sexual aggression
What are Davis & Daly’s critique on the theory of family?
- Human families might stay tgt coz of competition from other groups -> add on prediction 1: family stays if benefit of tgt > cost of staying
- Humans engage in extensive social exchange based on reciprocal altruism with non kin -> add on prediction 3: Help each other rearing children + unreciprocated help more prevalent in families vs no kin
- nonreproductive helpers (post menopausal) women -> little incentive
- to encourage their offspring to disperse -> stabilize family
