Rape : It is not always this cute…Holly Herrick and Ryan Schmidt

Background of EP

Key Premises:- Human behavior can only be understood by taking into account evolutionary

history as well as natural selection- Behavior depends on evolved psychological mechanisms- Mechanisms are functionally specialized to perform specific tasks/problems

related to reproductive success- Human brain is made of specific psychological mechanisms to produce behavior

Evolved Psychological Mechanisms: Information processing mechanisms housed in the brain that register and process specific information and generate as output specific behaviors, physiological activity, or input relayed to other psychological mechanisms

Adaptations of Rape with Animals

- Physical adaptations to increase capability of forced copulation- Male Scorpion Fly

- Orangutan

- Some beetle species (see below)

Rape in Humans

Rape: The use of force or threat of force to achieve penile-vaginal penetration of a woman without her consent

Rape results from adaptations formed from natural/sexual selection

Rape adaptations in Humans are psychological, not physical

Behavioral and learned factors increase the likely hood of the physical aspect of rape but do not fully explain the complex organized behavior of rape

Favored Explanations:- Rape is a product of specialized psychological adaptations- Rape is a by-product of other adaptations in the male brain

Evidence of Human Adaptations for Sexual Coercion and Rape

Rape must have been reproductively advantageous for human ancestors

Adapted features:- Recognition of highly fertile women (young age – peak fertility)

However, studies show that men prefer younger women in general

Rape is a possible reproductive strategy for all human males (not just low status/disadvantaged males)

McKibbin et al propose the existence of five types/contexts of rape

Disadvantaged Males/ Mate Deprivation Hypothesis

Males with no other means to copulate

Rape committed by men with low socioeconomic status and lower facial symmetry (indicators of low genetic quality)

Not necessarily indicator of strategic rape but rather higher propensity for risk taking in general.

Specialized Rapists

Males that are sexually aroused by violent sexual stimuli- More likely to rape fertile women (again, may not be specific to rape)

Because costs of rape may be high – it favors a rapist with the ability to have quicker arousal and ejaculation during rape situations

Known that men can unconsciously adjust sperm count, meaning that rapists might have this to increase odds of insemination during the single copulation

Adaptive advantage in rapid ejaculation during rape (minimizes costs to male)

Studies show 6% of rapes result in pregnancy vs. 3% in consensual mating

Opportunistic Rapists

Males who seek out receptive women, but willing to shift to force if the woman becomes non receptive. Tend to rape when cost is low and victim is vulnerable

Low evidence for this type of rapist

Support however is seen in how rape is less common for females with family members in the proximity

High-Mating-Effort Rapists

Males seem to be more sexually experienced, aggressive, with higher self-esteem (commonly believed to be psychopathic)

A male who believes that he has successfully mated in the past and has a long history of casual sexual relations is more likely to have incidents of sexual coercion in his past.

Belief of higher need/right for sexual encounters leads to increased sexually coercive behaviors (may result from high self-esteem)

Partner Rapists

Males motivated to rape due to increased sperm competition

Situation: husband finds out of possible infidelity of his long term partner

Due to internal fertilization makes paternity uncertain

Males who spend more time away from partners overall believe their partners are more interested in copulating with them

Positive relation between partners infidelities and sexually coercive behavior

Women’s Defenses

Bodyguard Hypothesis: women’s mate preferences reflect stronger/socially dominant men who possess Anti-Rape Powers!

BAM! POW!

Preeclampsia and spontaneous abortion may be a result of adaptations

Psychological pain – telling you to avoid rape next time (according to Thornhill and Thornhill . . . )

Reproductive age women are found to be more traumatized by rape

Strength (hand grip) varies during a woman’s menstrual cycle

Women in fertile phase of cycle perform fewer high risk behaviors; more attuned to detecting sexually coercive males

SummaryMore research into psychological adaptations for rape in males, and into the

preventative measures in females needs to be completed

surprise