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Desire for Variety - Coggle Diagram
Desire for Variety
Animals
gouldian finch
- socially monogamous, prefer birds that look like them.
- the colour of plumage indicates genetic compatibility.
- gouldian finches have a striking instance of genetic incompatibility within one species.
- offspring of incompatible birds have more than 60% higher mortality compared to compatible pairs.
- incompatible mates can increase a females finch's stress hormones.
fairy wrens
- form close bonds > male birds are very territorial, bit they spend more time courting other females than their partner
- highly sexually promiscuous > most of the chicks raised are sired by extrapair males
- the genetic health of the fairy wren population is increased by having more eggs fertilised by different males
primates
- chimpanzees live in multi-male and multi-female communities, promiscuously mating with each other > even though there is an alpha male.
- females have increased access to food resources.
- genetic evidence suggests that alpha males tend to father more offspring over time than non-alphas.
humans
- those couples matched soon after meeting were more likely to match based on physical attractiveness than those who formed their relationships well after meeting each other.
- is it possible to predict a romantic match before people meet?
- joel, eastwick and finkel 2017, psychological science
- had people answer questions on a computer program (self-report measures relevant to mate selection), then did a speed-dating program with members of the opposite sex. rated the desire and sexual attraction to each person. they used machine learning to try predict who would be the best fit for each other.
- not really. it is possible to predict the overall tendency that someone will be rated as desirable, and will be desired by others.
evidence for a desire for variety
- men and women differ in their strategies for short-term mates.
- men desired larger numbers of sexual partners compared to women.
- men were much more likely to desire more than one sexual partner "in the next month"
- carries over to married men, men living with another person, men who are dating, and single men.
- sexual promiscuity.
- more men were "strongly" or "moderately" seeking an extra partner compared to women.
- strong evidence for the evolutionary psychology view that men's short-term mating strategies are related to the desire for more partners.
- suggests that when men pursue a short-term sexual strategy, they are highly motivated by the desire for multiple mating partners, but for women, it is not as strongly connected.
- not affected by sexual orientation (males and females > bisexual females are more likely to want more sexual partners than other females)
does sexual orientation influence attitude towards casual sex?
- across the globe, men tend to have more positive attitudes toward casual sex as women.
- homosexual and heterosexual men share similar sexual attitudes towards casual sex; homosexual men tend to engage more in more casual sex than heterosexual men.
- homosexual and heterosexual women share similar sexual attitudes and behaviours towards casual sex.
emotional consequences of mate-seeking beyond monogamous relationships
- jealousy > complex emotion that encompasses fear of abandonment, rage, and humiliation.
when are women likely to agree to a brief sexual encounter?
- when the person is a high-profile celebrity, compared to a stranger.
- physically attractive, older than the participant
- men were not affected by celebrity status
- participants were around 22 and asked about older, married celebrities
Consequences
sociosexuality
- successful long-term relationships are associated with better psychological and physical health.
- relationship dissolution (breakups) is associated with significant health risks
- high divorce rates (30-50%) in numerous industrialised countries.
why are long-term relationships so difficult to maintain?
- although humans generally have the desire to form long-term pair bonds, there is a benefit to having non-committal sex with someone who isn't their partner.
- from an evolutionary perspective, it might be a way for humans to get high-quality genes for offspring.
- low motivation to pursue uncommitted sex (restricted sociosexuality): may never consider having sex with someone they aren't in a committed relationship with.
- high motivation (unrestricted sociosexuality): one-night stands, short-term relationships. test sexual satisfaction with a new partner or meet a need.
- likely that unrestricted people still get married.
- french et al 2019, psychological science
- husbands were relatively more unrestricted than their wives, but there was a moderate correlation between the sociosexuality of both couple members.
- unlikely that a person with a very restricted belief ended up marrying someone with a very unrestricted belief.
- increased likelihood of marital dissolution.
- relatively unrestricted sociosexuality was associated with less satisfaction at the start of the marriage.
- people with unrestricted partners had a faster decline in satisfaction over the first several years of marriage and predicted a higher likelihood of relationship dissolution.
- if one or both spouses take a broad view that uncommitted sex is okay, that can contribute to the failure of a long-term relationship.
- does not affect the marriage if there is a consistent, satisfying sexual relationship, and if there's low stress in the marriage.
- does not say if unrestricted sociosexuality is a positive or negative trait.
- there needs to be studies done on those in consensual non-monogamous relationships.
paternity certainty
- evidence suggests that human females have a history of having sex with someone other than their partner.
- may be unconsciously attempting to maximise the quality of the genetic makeup of their child.
- only works if her partner is unawware.
- maternal lineage is easy to determine > she gets pregnant and pops it out.
- paternity uncertainty is a major problem for males to solve.
- fetal dna in the mother's blood can be paternity tested as soon as 8 weeks into the pregnancy.
- resemblance
- for some couples, there might be enough trust that there is no question of paternal lineage, but there are other reassuring influences.
- family of the mother are more likely to say that the baby looks like its father.
- only happens when the father is present in the relationship.
- at all ages, children resemble parents much more than what would be expected by chance, however, there is a difference in which parent the kid looks more like depending on the age and sex of the kid.
- features that are salient in men and women might be more visible at different ages
- may be evolutionary: the mother is the primary caregiver > increase in perception of resemblance between a kid and the father to reassure the father and get him to invest more time and resources.
- at birth, mums ascribe more resemblance to the father of their newborns > opposite to what unrelated people think > fathers do the same.
- facial resemblance is an important cue for parents to assess paternity.
- rate of misattributed paternity
- the media publishes high statistics: 9-30%
- australian researchers traced the 30% estimate to unpublished data from 1972 by a british doctor in a small sample of parents
- data from samples across a broad range of societies suggest the rate of misattributed paternity is between 1 and 3%.
- some practical and ethical limitations to population-wide paternity testing.
- for men with high paternity confidence, there is a very small rate of non-paternity (<2%)
- the rate of non-paternity is highest in those who have low paternity confidence.
- maybe because those people were so suspicious already that they took part in the lab test, whereas those who are confident wouldn't be using those tests at all.
infanticide and filicide
infanticide- cinderella effect:
- higher incidences of child abuse and neglect by step-parents, than by biological parents.
- might reflect a basic, recurring tension in human society.
- extreme and rare cases: infanticide > intentional killing of infants.
- evolutionary perspective: argued that stepfathers lack biological relatedness to the children, and so are less invested in the children than biological fathers. stepfathers could be more prone to frustration and irritation and hence act more violently.
- more recent estimates indicate the number of child deaths perpetrated by stepfathers is lower, and the proportion of children with stepfathers is higher.
- negligible risk for older (>5 years) stepchildren
- stepfathers tend to be younger than biological fathers
- the risk to young stepchildren is about 6 times the risk to biological children > not as dangerous as earlier research suggested
filicide
- the killing of a child by parent or a parent equivalent
- 20 filicide incidents recorded each year in Aus from 2000-2011/12.
- risk factors
- criminal history
- acrimonious (non-amicable partnership breakdown and post-separation parenting disputes.
- domestic violence
- parents being affected by mental illness/substance abuse
- having multiple risk factors places a family at the greatest risk
- evolutionary perspective: focuses on the huge costs of being a parent
bruce effect
- the termination of pregnancies by the female after exposure to unfamiliar males.
- strong evidence in lab rodents
- direct evidence has not been found in the wild (natural conditions) until recently.
- very strong evidence found in the theropithecus gelada
- female geladas terminate 80% of pregnancies in the weeks after the dominant male of the group was replaced.
- the usual rate of pregnancy failure is closer to 2%
- the new dominant male will kill the young fathered by the old dominant male.
- female geladas go for 3 years between pregnancies > longer than the typical reign of a dominant male.
- the quicker he kills the infants, the sooner the females will become fertile again, and the sooner he can father his own children
Background
- in males, the benefit of having an increased number of sexual partners means that more offspring are likely to be produced and our genes are more likely to be passed on to subsequent generations
- females invest more time and energy into offspring than males
- females desire more sexual partners for different reasons
- more partners increases the quality of output in birds
- more partners increase access to resources to raise offspring