Week 19 Flashcards
What are the assumptions of evolutionary psychology
psychological phenomena arise out of biological processes
biological processes shaped by evolutionary forces
many aspects of human behaviour, can be understood in terms of their adaptive functions
One, gene, one disorder (OGOD)
Theorizes that one gene is responsible for one disorder, or a single specific gene is the causal agent in a specific disorder
Why is OGOD false?
Many mental disorderes are affected by more than one gene
Allelic association designs
Studies that compare affected and unaffected individuals, regardless of their kinship status
Fixed genes
Genes that improve an offspring’s chance of survival are more common in the population until they are no longer important for survival while genes that do not affect survival continues to vary
Evolutionary fitness
- Changes in evolutionary fitness require additive genetic variance, genetic variance due to gene dosage, as opposed to interactions among different genes, and is responsible for the resemblance between parents and offspring
- If additive genetic variance for fitness-related characteristics is present in a species, then there is opportunity for further selection
- When the population reaches maximal fitness, the additive genetic variance is zero, meaning the genes have gone to fixation
- Inclusive fitness is the reproductive success of those individuals who share the same genes
Influences of psychological traits
Genes, non-shared environment, and then shared environment
What are the two interrelated causes of behaviour?
The structure and chemistry of the organism (largely genetically determined, some aspects vary significantly in humans such as height or an extra chromosome) and the environment (genetic differences are meaningfully related to different behaviours and developmental outcomes in current environments
Evolution has no foresight and humans are not more evolved than other animals
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A specific allele may create a different genetic load at different times or in a different environment
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Genetic load
The reduction in overall evolutionary fitness for a population compared to what a population would have if all individuals had the most favoured genotype
Naturalistic fallacy
The belief that characteristics produced by evolution are either natural and good or unnatural and morally bad rather than amorally selectionist
Amorally Selectionist
the belief that natural selection is the fundamental factor in evolution
What are the two common misconceptions of evolution?
Naturalistic fallacy and genetic deterministic fallacy
Genetic deterministic fallacy
The belief that genes determine behaviour independently of environmental influences
All characteristics selected by evolution are expressed in an environment and are often influenced by environmental context
Facultative behaviours
Behaviours that are determined by the immediate environment
For example, cross-cultural differences in parenting
Obligate behaviours
Behaviours that develop to a large degree independently of variations in environmental process
For example, the experience of sexual attraction, regardless of where it is directed
Evolutionary theories are environmental and selectionist in orientation as past environments are posited to have selected characteristics of organisms by acting at the level of individual genes
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If an organism undergoes adaptation that reduces survival in the current environment what happens?
Surviving population does not have the adaptation
If an organism undergoes adaptation that has no effect on survival in the current environment what happens?
Some of the population has adaptation
If an organism undergoes adaptation that increases survival in the current environment what happens?
Most of the population has the adaptation
What is the traditional belief of modification of cell inheritance?
It occurs as a result of alterations in the DNA sequence
What does modern evolution theories assume?
An organism cannot past traits it has acquired to its offspring because the acquired trait would not be expected to result in alteration of the DNA sequence
Why has epigenetic modification contradict the assumptions of modern evolution theory?
Changes in cellular inheritance not due to changes in the DNA sequence
Epigenetic modifications can occur because of environmental experience
This raises the possibility that an acquired characteristic could be inherited by offspring
What is the adaptionist view of the phenotype?
What is the function of a particular feature?
What are the four criterion adaptionist researchers argue that adaption must meet?
It is obviously designed to accomplish some biological purpose
It operates in a similar manner over cultures and time
It is plausibly related to reproductive and survival success in ancestral environments
It is not more simply explained on other grounds
Species - typical
Genes that are uncommon decrease the likely good over time and eventually they disappear if they are unable to be passed on, as the typical or dominant gene would take over
Sexual preferences as adaptation
The fact that male prefer sexual partners who have reproductive capability, such as sex, youthfulness, body shape, absence of genetic anomalies and developmental precision, strongly indicates that it is an adaptation
How does the tuning of male sexual interests toward female reproductive capability meet the adaptation criteria?
It maximizes attraction to and motivates behaviour toward reproductively viable partners
It is similar over cultures and time
It is plausibly related to reproductive and survival success in ancestral environments in that men who had this sexual preference system were likely to out-reproduce those men who did not
It is not more parsimoniously explained on other grounds, such as a general preference for particularly shaped objects
Parental investment
The energy, time, resources, and opportunity cost associated with producing offspring
Parent investment costs contrasts with mating opportunity cost, that is the effort and costs incurred in securing and preserving mating opportunities
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Which sex has greater selection pressure to compete for access to members of the other sex?
The sex with the higher potential reproductive rate
How does sex affect morphological structures and behaviour?
It often creates sex-specific morphological structures and changes in behavioural tendencies
When are females more selective about sexual partners?
When the females have to incur the larger investment
Also there is less competition between males and they experience smaller variations in reproductive success
When do females have to fight for access to males?
When females incur the smaller investment, they are also less discriminating than males are and experience large variations in reproductive success
Polygyny
sexual behaviour where one one male mates with more than one female, but females only have one males
What effect does polygyny have on males?
Some males end up having a lot of reproductive partners while must have very few or none at all
Why are males expected to take more risk?
Because they have greater reproductive variance
Why do males conduct risky behaviour
It is often related to competition for status, resources, and mates, and are most common among young men of poor economic prospects
What are some of the proximal causes of sex differences in mating strategies, risk acceptance, and aggression caused by?
Hormones
There is a link between ecological selection pressures, hormones, and behaviour
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What are sex hormones made of?
Steroids (lipids) produced from cholesterol
How do sex hormones work?
Sex hormones pass through the cell’s plasma membrane and bind to the nuclear membrane receptors inside the cell
The combined steroid hormone-receptor complex enters the nucleus, binds to the DNA and acts on genes
Steroids within cells containing appropriate receptors act on particular genes
Why are steroid receptors psychological interesting?
They have specific motivational effects and are highly specific
Why do steroid receptors act as?
They act as organizers of foetal neural tissue and as context-sensitive activators of biologically significant behaviours throughout life
What are the two forms of sexual selection?
Epigamy and intrasexual selection
Epigamy
A form of sexual selection based on the alteration of appearance in some way that provides greater attraction
Intrasexual selection
produces characteristics that provide reproductive advantages, sometimes even to the detriment of survival advantages
Males are often subjected to sexual selection pressure of both types
How do disadvantaged males male?
By using alternative strategies such as smaller bluegill sunfish who create a sneaky mating strategy
What is the concept of conditional strategies
Individuals are genetically the same, but adopt different behaviour tactics, depending on conditions they encounter during their lifetime
Mathematics of inheritance
The idea that organisms share varying numbers of their segregated or polymorphic genes with their relatives of common descent
What percentage of their alleles do organisms share with their first degree relatives?
50%
What percentage of their alleles do organisms share with their second degree relatives?
25%
What percentage of their alleles do organisms share with their third degree relatives?
12.5%
What does one mean when they say ‘altruistic behaviours in animals are found to be nepotistic’
there is a tendency to favour relatives over non-relatives regardless of circumstances
Animals benefit from this by increasing their own fitness as well as their relatives
What is reciprocal altruism?
Altruism in which people behave altruistically toward one another because they are confident that such acts will be reciprocated toward them or their kin
Why do animals partake in cooperation?
The gain through cooperation is greater than the sum of the gain obtained by each party without cooperation
Game theory
Mathematical approach used to study and predict the evolution of social interacts where the costs and benefits of cooperation are compared to the benefits and costs of not cooperating
Why might the mother’s immune system try and attack the foetus?
They only share 50% of their DNA which means they lack genetic identity
How does the foetus prevent the mom’s immune system from attacking it?
Through the placenta which does not display human leuocyte antigen markers
The foetus also defends itself actively
Why may there be competition between the foetus and the mother?
They do not have identical genetic interests
It may be in the foetus’ interest to obtain more maternal resources than the mother is willing to give
What happens when the foetus produces its own hormones?
The mother becomes insensitive to the large quantities
How does the foetus attempt to maximize its share of each maternal meal?
raising the mother’s blood pressure
How does the mother protect against this?
placental cells also kill the muscles in the arteries leading to the womb, so it cannot contract it and thus has to spiral these arteries to increase their resistance to blood flow
What happens when females mate with more than one make?
maternal-paternal gene conflicts
the partially divergent genetic interest of parents and child shows itself later by influencing the child’s behaviour
A child who receives large amounts of quality parental investment behaves in a way that supports or aids the child whereas little investment develops behaviours that help them survive without help
What are the six basic emotions?
Surprise happiness fear anger disgust sadness
How were early men limited in their reproductive success?
by the number of fertile partners, men needed to acquire status and wealth to be attractive to women
How were early women limited in their reproductive success?
The resources available to them to raise their offspring, women competed by being the most fertile: healthy and young
How did early men make mistakes in reproduction?
by wasting their resources on a child that was not theirs
How did early women make mistakes in reproduction
By mating with men who did not invest their resources in her child
What are characteristics ancestral males looked for in women?
fertile appearance, partner novelty, sexually jealous based on the extent of resources, socially and materially ambitious
What are characteristics ancestral women looked for in men?
the emotional commitment of the partner, health, status, and resources, the observed pattern of generosity by the potential partner
What does a women’s jealousy focus on?
her partner’s emotional commitment to her
What does men’s jealousy focus on?
his partner’s sexual fidelity
How does marital violence arise?
a man’s desire to control the reproductive capacities of women that they devoted their resources to
What is the most common source of conflict?
male sexual proprietariness and jealousy
Men are more interested in partner variety, more willing to have impersonal sex, and have a greater propensity to seek extra-pair romances
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What does evolutionary psychology not do?
deny the environment also plays an important role
imply that group differences always trump individual variation within groups
provide ‘moral justification’ for problematic behaviour
Unrestricted sociosexual orientation
pursuit of short-term casual sexual relationships
Restricted sociosexual orientation
Pursuit of long-term committed sexual relationships
Why are men attracted to young women with sexual maturity
fertility peaks at early twenties to mid twenties
Why is sexual infidelity more frustrating to a man?
They could spend their resources raising another man’s kid
Why is emotional infidelity more frustrating to a man?
it could signal their mate may direct resources to other women
Why does the double shot hypothesis challenge evolutionary explanation?
Women believe emotional infidelity also implies sexual infidelity but not the reverse
Men believe sexual infidelity also implies emotional infidelity but not the reverse
