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
