An Evolutionary Perspective of Human Female Rape

Abstract

This thesis assessed whether rape is an adaptive mating strategy. which was naturally selected for in our ancestral past. It investigated a number of constructs. namely: fertility value; victim-offender relationship; socio-economic status; rape proclivity; actual sexual aggression; and sociosexual orientation. There were two types of studies: studies 1-3 involved archival data, e.g. the use of criminal statistics. and studies 4-7 assessed participant data, e.g. rape attitudes. Study 1 found that fertility value (FV) was related to rape prevalence, as was reproductive value (RV). In addition, offenders with a nonreproductive sexual preference tended to rape a victim with a low FV. and offenders who committed a secondary offence tended to rape a victim with high FV. Study 2 found that there was a smaller number of offences committed against strangers and partners, and a larger number committed against step-relatives and acquaintances. More rapes were committed by low status than high status men. even when the base rate was accounted for.
Study 3, showed that there was a relationship between the population gender ratio and rape prevalence. However. the covariable population density was positively related to rape
prevalence. Study 4- found that there was more disapproval of a depicted rape committed by a low status offender. A low status offender who raped a victim with low RV attracted
more disapproval. Study 5 showed that marital rape was disapproved of more than both stranger and acquaintance rape. Individuals with a short-term mating strategy disapproved of rape more than those with a long-term strategy, and a long-term strategist disapproved of
a marital rape less than a short-term strategist. Study 6 found that those who possessed a promiscuous ideology perceived their future life to be limited, in particular the likelihood of being happily married. There was no relationship found between perceived future life and
sexual aggression. In study 7. it was found that those who had a more unrestricted sociosexual orientation were more likely to have asymmetrical bodily traits (e.g. ear height.
finger length). and that the right hand 20:40 digit ratio (a measure of prenatal testosterone)was significantly related to actual sexual aggression. Overall. there was partial support for rape as an adaptive mechanism. but the studics wcre also consistent with a by-product explanation of rape.