Evolutionary Evolutionary Perspectives Perspectives

on Rapeon Rape

Starting PointsStarting PointsLanguage: “Victims” vs. “Survivors”Averages: Individual differences in

rapists, victimsMale rapists, female victims

Definitional Issues (1)Definitional Issues (1)Definitions:

Penile-Vaginal? Force or threat of force? Resistance?

“Copulation involving either the individual’s resistance to the best of his/her ability, or the reasonable likelihood that such resistance would result in death or bodily harm to the victim or others whom he/she commonly protects.” (Palmer, 1989)

Definitional Issues (2)Definitional Issues (2)

Semantic IssuesSemantic IssuesRape vs. forced copulation

Animal models“They know not what they do”

Sex vs. violence Rapist’s or victims perspective?

Attractiveness, harm to victim, sex & affection

Legal ramifications

Modern Historical Context (1)Modern Historical Context (1)Miller (1931)

Rape is unique to humans because of reshaping of the pelvis

Brownmiller (1975) Non-human animals do not engage in

rape because mating in the wild is controlled by the female estrous cycle

Feminist theory During rape, “the sexual act is not

concerned with sexual gratification but with the deployment of the penis as a concrete symbol of masculine social power” (Sanday, 1990)

Rape "is nothing more or less than a conscious process of intimidation by which all men keep all women in a state of fear" (Brownmiller, 1975)

Modern Historical Context (2)Modern Historical Context (2)

Non-Human Animal ResearchNon-Human Animal ResearchResearch has been conducted on non-

human primates, fish, frogs, elephant seals

Considerable focus has been given to waterfowl Synchronicity Mate guarding Sperm competition following FC Predictive models

Insect ResearchInsect ResearchWing perching in the damselflyPanorpa scorpionfly (Thornhill, 1980)

Three mating strategies

Likelihood of Committing Likelihood of Committing RapeRape

Rape scenario study (Malamuth et al, 1980) 17% endorsed rape scenario 51% endorsed scenario with the

condition that they wouldn’t get caught

Additional 21% scored middle of the scale

Evolutionarily-relevant information (Thornhill & Thornhill, 1991) Over-representation of women of high

reproductive age (RA) Women of RA more likely to be

subjected to penile-vaginal rape RA associated with ejaculate in the

reproductive tract

Rape & EPRape & EP

Women of RA suffer more than post-RA women or pre-RA girls

Married women suffer moreNegative correlation between signs of

violence and sufferingPenile-vaginal rape caused more

suffering only in RA womenRelationship to rapist (stranger, friend,

family)

Psychological PainPsychological Pain

Thornhill & Thornhill (1990a,b,c,d)

Rape AvoidanceRape AvoidanceChavanne & Gallup (1998)

During ovulatory phase of menstrual cycle, women engage in fewer risky behaviours

Participants taking birth control pills showed little variation

Effect is not an artifact of reduced sex drive or reduced general activity

EP Theories: By-productEP Theories: By-productSymons (1979), Palmer (1991)

Insufficient evidence for adaptation Rape is on a continuum of behaviours

and is a byproduct of other adaptations (e.g., partner variety and impersonal sex)

Ellis (1989); Malamuth (1996) Biosocial factors (e.g., delinquency)

and neurological differences

EP Theories: AdaptationEP Theories: AdaptationShields & Shields (1983)

Victim “vulnerability detector”Thornhill & Thornhill (1983)

Mate Deprivation hypothesisAgreement between adaptationist & by-

product theories Facultative vs. obligate genes Psychological pain & mate choice

violation

Synthesis (1)Synthesis (1)EP framework can integrate proximate

& ultimate causes into an overarching framework (e.g., Malamuth, 1996)

Synthesis (1)Synthesis (1)EP framework can integrate proximate

& ultimate causes into an overarching framework (e.g., Malamuth, 1996)

Delinquency

Attitudes (Violence)

Sexual Promiscuity

Hostile Masculinit

y

Coerciveness against Women

Parental Violenc

e

Child Abuse

Feminists vs. evolutionists?Sex vs. violence?

Muelenhard et al (1996): Control/consentNew research direction

Rape as a short-term mating strategy and the Micro-Mate Deprivation hypothesis (Lalumière et al, in preparation; Lalumière et al, 1996; Lalumière & Quinsey, 1996; Quinsey & Lalumière, 1995)

Synthesis (2)Synthesis (2)

The Wrap-UpThe Wrap-UpDefinitional & semantic issuesHistorical contextNon-human animal & insect researchRape in humans

Likelihood of committing, evolutionary evidence, psychological pain, avoidance

Rape theories (adaptation vs. by-product)New research directions

Things to ComeThings to ComeStatus, Prestige, & Dominance

Dominance hierarchies EP theories of dominance Multilevel-selection and hierarchies Submissiveness