Evolutionary Psychology mcq notes
Attempts by evolutionary psychology to explain altruism and group selection:
"The overall finding on altruism is one of sex similarity" (Maccoby and Jacklin, 1974, p.354 Very hard to explain compared to aggression ("the selfish gene")
Give three basic observations about human sexual and parenting behaviour (3)
- Unequal investment: females must invest a great deal in rearing; males are very fertile, human females have very low ability to reproduce - females' eggs deteriorate and run out long before death (comparatively!) - non-reproductive sex occurs (e.g., contrasts with orangutans) - views of sexual behaviour affect views on social living, aggression etc. (e.g., are we polygynous or monogamous?) Theories of family life etc all hang off sexual theory]
What is evolutionary psychology? (some key premises)
-->EP examines psychological structure from a modern evolutionary perspective. An approach that views human nature as the product of a universal set of evolved psychological adaptations to recurring problems in the ancestral environment. -->Seeks to identify which human psychological traits are evolved adaptations - that is, the functional products of natural selection or sexual selection in human evolution. Evolutionary psychologists argue that much of human behavior is the output of psychological adaptations that evolved to solve recurrent problems in human ancestral environments. --> Evolutionary psychology adopts an understanding of the mind that is based on the computational theory of mind. It describes mental processes as computational operations, so that, for example, a fear response is described as arising from a neurological computation that inputs the perceptional data, e.g. a visual image of a spider, and outputs the appropriate reaction, e.g. fear of possibly dangerous animals. 1) The brain is an information processing device, and it produces behavior in response to external and internal inputs. 2) The brain's adaptive mechanisms were shaped by natural and sexual selection. 3) Different neural mechanisms are specialized for solving problems in humanity's evolutionary past. 4) The brain has evolved specialized neural mechanisms that were designed for solving problems that recurred over deep evolutionary time, giving modern humans stone-age minds.
Give three proximate causes as evidence in favour of monogamy, and a ultimate/evolutionary explanation:
-Humans make strong pair-bonds -Both males and females are empathic and nurturing -Offspring are vulnerable and dependent- need biparental care (would be too much of a risk to only have one parent!) --> human reproductive success is better guaranteed by shared parental investment Humans have the immune system of a monogamous primate (Nunn et al., 2000)
Buss et al. 1992; "The Gender Gap in Jealousy"; which scenario causes the most distress to each gender?
-Jealousy has adaptive value; without it sex and parenting are exposed to threat. -Identifying which scenarios will cause jealousy for men and women, is relevant to sex differences in parenting. Men are more distressed by: sexual infidelity (issue = paternity uncertainty?) Women are more distressed by: "emotional infidelity" (issue = commitment to provide?) Natural selection: would still select against fully equal investment Behaviour in a man's best genetic interests and that in a woman's best genetic interests may be different
Which two key issues should any decent EvoP account be able to explain?
-Sex and Parenting -Aggression and Cooperation
What is controversial about group-selection?
Altruism and group-level adaptation: Key problem: we have to assume GROUPS of altruists who are more successful than non-altruists The argument is that group selection seems to contradict natural selection: the supposed rule is that selection is of individuals and not groups The evidence and theory on group selection is still contested (E.g., the evolutionary psychologist Pinker opposes it on grounds of vagueness and poor science) Pinker: the false allure of group selection http://edge.org/conversation/the-false-allure-of-group-selection
Are chimps really altruistic, according to Silk (2005)?
Are chimps really 'altruistic' (Silk, in Nature, 2005) Chimps are given the opportunity to get a reward for themselves OR Get a reward for themselves and also a free extra reward for another chimp (behind a glass panel) Entirely indifferent to the welfare of others Cooperative hunting occurs, but chimps are not other-oriented: their behaviour is selfish or reciprocal
Four arguments for aggression being an adaptation (4)
Arguments for aggression being an adaptation: -Frequent, with an effective functional design -It serves a purpose (doesn't arise randomly), e.g. increases when food is scarce and is targeted -Is an organizing influence (dominance systems) -Success in combat correlates with success in mating -Integrated with physiology and psychology (sex differences, etc.) e.g., sexual dimorphism relates to value of aggression and there are psychological sex differences in aggression (Sexual dimophism; two distinct genders/forms, differences in characteristics/appearance beyond the diffs in the sex organs themselves. -Aggression is not random or a byproduct Primates: cannibalism, infanticide, murder are common (patterned) Wilson: frequency of murder is so high among animals that it must be "normal" behaviour e.g., infanticide: = 1/3 of infant deaths in gorillas Need to remember that what is in the genetic interests of a male may not be in the genetic interests of the female - Aggression may not be maladaptive.
Evidence undermining hidden ovulation:
Austrian nightclub experiment: higher female sex hormones (oestradiol and testosterone) more provocatively dressed. (Grammar et al., 2004; Durante et al., 2008) men are more jealous at ovulation - they increase guarding (Gangestad, 2007) men find the scent of ovulating women more attractive: e.g., strippers get more tips nearer to ovulation (Miller et al., 2007)
Give e.g.s of how altruism works for: -baboons and meerkats -Birds (esp. kookaburras)
Baboons and meerkats: Dominant males will look-out rather than feed Birds: alarm calls distract attention of predator.. towards the caller! Kookaburras: look after others' young - serves to enhance chances of relatives' genes surviving
Why would male parental care in general be a bad evolutionary gamble? (2)
Because: (1) only the mother's genetic investment is certain (2) males are better served by competing for access to other females (males are very fertile, human females have very low ability to reproduce - females' eggs deteriorate and run out long before death)
What are the two approaches in psychology that relate biological inheritance to behaviour?
Behavioural genetics: (asking why do people differ?) Evolutionary psychology: Focuses on the adaptive function of our shared instincts (asking why are people similar?) Evolutionary psychology= about how we are adapted. What is the fit between the human, and the environment that they are in? Do typical human social and sexual behaviours reflect adaptations to environmental conditions?
Give two pieces of Evo evidence against the social sciences view that aggression is learned:
But sex differences in aggression appear by 17 months, before the labels and stereotypes that generate sex differences, according to standard social learning theory, are understood (Archer and Cote, 2005) Human male aggression peaks at 16-24. This coincides with the time when physique peaks, reputations and mates are acquired. What is learned by being in society is not violence but control. (one POV!)
Briefly describe changes in theories about sexual strategy. What may have caused the changes in these theories? Nunn et al. 2000
Changes in theories about sexual strategy: Are these stories that reflect changes in political fashions from the 1970s onwards? 1970s- dominant theories: comparing humans to other apes, esp. gorillas, with dominant male and harem of females (reflective 80s/90s: pair bonding More recently: 21st century: female infidelity and sperm competition Some evidence for this: summarise Nunn et al. (2000): Humans have the immune system of a monogamous primate "EPCs", Extra-Pair Copulations: Mathematically, pair bonding works best for females' genetic interests if combined with female infidelity, e.g., evidence from birds Monogamy: theories that emphasized male dominance and infidelity were superseded by theories that emphasize monogamy Most recently the emphasis has been on female infidelity -monogamy and pair bonding work best for females' genetic interests if combined with female infidelity
Troisi, A., & Carosi, M. (1998). Female orgasm rate increases with male dominance in Japanese macaques.
Claimed that primate (and human!) female orgasm is an adaptation that supports female choice of dominant males. Notorious study! (Other data suggest that female monkeys prefer to mate with new, unfamiliar males... a re-reading of the Troisi and Carosi evidence implies that females prefer new non-dominant outsiders rather than simply dominant males
Give an argument about non-procreative sex and concealed ovulation in humans, used to support the idea that human are pair bonders:
Concealed ovulation, and sexual receptivity throughout month! female ovulation is not signalled - and sexual receptivity is not confined to the time of ovulation The idea that concealed ovulation promotes non-procreative sex, and this then reinforce pair bonds may be insufficient: chimps have lots of non-procreative sex but don't pair-bond; birds have none but cooperate in parenting. I.e. Women do not advertise their sexual peak.
Why do women have orgasms? Orgasms as a test of evolutionary psychology accounts. Is women's orgasm an adaptation?
Even though female orgasm seems to be the 'right kind' of candidate for a well-defined, evolved, functional mechanism that serves female reproductive strategy, evolutionary psychologists have struggled to understand it- arguably the most contentious question in study of the evolution of human sexuality!
What kind of behaviours are good candidates for evolutionary adaptations?
Evolutionary psychologists hold that behaviors or traits that occur universally in all cultures are good candidates for evolutionary adaptations including the abilities to infer others' emotions, discern kin from non-kin, identify and prefer healthier mates, and cooperate with others.
How does evolutionary psychology view the brain?
Evolutionary psychology adopts an understanding of the mind that is based on the computational theory of mind. It describes mental processes as computational operations, so that, for example, a fear response is described as arising from a neurological computation that inputs the perceptional data, e.g. a visual image of a spider, and outputs the appropriate reaction, e.g. fear of possibly dangerous animals. MODULAR!! EPs argue that the mind has a modular structure similar to that of the body and with different modular adaptations serving different functions (just like the structure of the body, with different modular adaptations serving different functions, e.g. brains and heart!) EP views the human brain as comprising many functional mechanisms, called psychological adaptations or evolved cognitive mechanisms or cognitive modules, designed by the process of natural selection. Examples include language-acquisition modules, incest-avoidance mechanisms, cheater-detection mechanisms, intelligence and sex-specific mating preferences, foraging mechanisms, alliance-tracking mechanisms, agent-detection mechanisms, and others.
**Proximate and ultimate causes What kind of questions does Evolutionary Psychology focus on? [See slide Example of a student exercise: The Austrian nightclub experiment:]
Evolutionary psychology focuses primarily on the "why?" questions, while traditional psychology focuses on the "how?" questions. Ultimate cause: WHY A BEHAVIOUR EXISTS/ adaptive significance (In context of EvoP: Why a species evolved the structures (adaptations) it has) Proximate cause (the immediate cause): The environmental triggers or biological processes that underlie behaviour (e.g., what psychologists usually measure in tests) How an individual organism's structures function (HOW A BEHAVIOUR WORKS The idea is that natural selection sculpted the mind and behaviour- those who negotiated well/ hunted skilfully/ parented/ defended/ dominated, etc. were more reproductively successful If try to make a story about where an adaptative behaviour originated from 250,000+ years ago, I have no data to hand. This is where a lot of psychologists draw the line- are not willing to use it as an explanation. It's ok to speculate about the ultimate cause, but not to think you have the ultimate answer!
Give an example of female aggression from the animal world
Female aggression (Spotted sandpipers) Males look after young --> a shortage of males Females compete for males This reinforces the female tendency to be larger, more colourful and aggressive. - Each species' behaviour is moulded by its previous adaptations there is chimp way of being social, a sandpiper way of being social, and so on- each species takes its own route and solves problems in different ways as a result
What is the tension between the concepts of natural selection and group selection?
Group selection= The idea that one mixed bag of individuals can be "selected" as a group over other heterogeneous groups from the same species. Group selection is a proposed mechanism of evolution in which natural selection is imagined to act at the level of the group, instead of at the more conventional level of the individual "for the good of the species" Group selection seems to contradict natural selection: the supposed rule is that selection is of individuals and not groups
Is the proximate account of the evidence adequate?/Why should evolution be considered in a broader (evolutionary) context?
In some species, females become MORE aggressive with oestrogen treatment (e.g., chimpanzees). Twin studies or individual differences in aggression don't reveal why aggression exists. Aggression is elicited by particular stimuli (e.g., red-bellied objects for sticklebacks) Environmental factors: availability of food (e.g., baboons fight over a kill, but not over fruit) Season: e.g. competing over females There are no simple genetic, hormonal, or environmental factors that fully explain differences in aggressiveness. This suggests that aggression must be seen in a broader context: i.e., the adaptive history of the species
How is paternal uncertainty created by concealed ovulation, and what is the potential evolutionary pay-off of this?
Infanticide common in animals- e.g., 1/3 of infant deaths in gorillas Conspicuous ovulation female will monopolized by dominant male when she is fertile clear paternity. Concealed ovulation - dominant male can't be there all the time; many males may copulate with each female (e.g. vervets) Confuses paternity and undoes monogamy Payoff: reduces infanticide. Males cannot be sure if the baby is theirs or not. Promiscuous: everyone mates with everyone else, therefore no one knows who is fathering who. Females have the benefit of there being no reason for a male to kill any of their offspring. Deliberately confuses things.
Which gender is greater aggression shown towards overall?
Males! The argument that women are defending themselves against male attack is not supported by studies that show that women more often than men report initiating the attack (e.g., DeMaris, 1992). Archer and Cote (2005): both sexes show greater aggression towards males!
Are humans monogamous? What did Daly and Wilson say?
Monogamy is practised by only 15% of human societies (Badcock, 1991) The norm is one male and many females (polygyny) **Daly & Wilson think that humans are like species that have low male parental investment: this emphasizes male competition for females, male infidelity, sex differences in aggression, male jealousy etc., and that females select accordingly
Criticisms/points of contention with evolutionary psychology:
Post-hoc rationalization: formulated "after the fact." Rationalisation (also know as making excuses), is a defense mechanism in which controversial behavours or feelings are justified and explained in a seemingly rational/logical way to avoid the true explanation, and so are made tolerable or even admirable by plausible means.
What evidence did Sillén-Tulberg and Møller (1993) give to support concealed ovulation/parental uncertainty as evidence for non-monogamic traits?
Primate Evolution: Sillén-Tulberg and Møller (1993) 10/11 monogamous species have concealed ovulation (BUT 22/32 species with concealed ovulation are promiscuous, contrary to theory 1) Therefore theory 2 is supported. Key finding: Monogamy never evolves alongside strongly advertised ovulation
Define adaptive significance:
Refers to how adaptive a particular characteristic is, to the beneficial qualities, in terms of increased survival and reproduction, a trait conveys.
Please explain the relationship between the terms "sociobiology" and "evolutionary psychology"
Sociobiology: interested in social behaviours . Biological basis of our social interactions (sex, parenting, aggression, cooperation) Dates back to 20th century. Lec: There is no cut-off point at which behaviour is no longer biological. Your biology is absolutely who I am. Can we have a biological account that is also enough to explain some behaviours? Evolutionary psychology: interested in all behaviours- the biological basis of all our behaviours (thinking and decision making etc.) Not just sex/parenting/aggression/cooperation. Not just interaction. I shall not distinguish between the two. Both ask questions about "Why?" E.g., if there are sex differences in aggression, why would this be adaptive in human evolution? I won't draw a distinction between these- its an empty debate- no punishment for not distinguishing between these in essays.
Aggression (gender differences): Two obvious facts (2) Two purposes of aggression (2)
Some obvious facts: (i) Males are more aggressive. (ii) Male aggression is by males against males. Females are usually spared. Is this pattern adaptive (shaped by a history of adaptations?) Problem of definition/classification: What is aggression? E.g. territorial, destructive, dominance aggression, sexual aggression (e.g., baboon harems), parental discipline, etc. Function: overall, there are two purposes of aggession: sexual competition resource competition
Female behaviour: competition and selection of males
Spotted sandpipers- Males look after young shortage of males. Females compete for males, reinforcing the female tendency to be larger and more colourful Human females- fat on breasts and hips has no physical function. Women must advertise and compete for males. Male figures- females prefer high status males with resources (e.g., see Buss), hence may prefer muscular and aggressive males Birds: Maternal investment is influenced by the quality of the male partner (e.g., attractiveness, song) life-history theory
Name two key ideas in evolutionary theory:
Two key ideas: Adaptation: Natural selection: the best-adapted survive (do not need more detail than this)
Explain how altruism works for Vampire bats:
Vampire Bats (Wilkinson, 1984) Bats feed kin and also unrelated animals who have not fed A hungry bat loses energy faster than a full one therefore: benefit > cost Bats associate with a group Bats are likely to need help themselves, and donors will be favoured later
