Evaluation of responses to risk situations in women and its relation to the menstrual cycle from an evolutionary perspective

This thesis aimed to assess the hypothesis that women have evolved a rape avoidance mechanism that is particularly active during ovulation when chance of conception is highest. It assessed whether fertility-related differences in response to risk were specific to rape risk, or generalised to all threats. This is not known from previous research. In Study 1, fertility did not influence handgrip strength or subjective responses to scenarios that varied in the risk of rape. However, in Study 2, women increased their handgrip strength when fertile compared to nonfertile in response to all potentially threatening scenarios involving men, but not the female-perpetrated assault scenario, which involved danger but no immediate risk of rape. Women also felt at higher risk of rape and male-perpetrated assault when fertile compared to nonfertile. In Studies 3 and 4, fertility influenced attention to potential reproductive threats (angry versus neutral male and female faces), but not general threats (fear-relevant versus neutral animals). Against expectations, women were faster to detect neutral faces when fertile compared to nonfertile (Study 3). In Study 4, fertile women were slower to fixate on angry compared to neutral faces, but spent a higher proportion of time fixating on angry versus neutral faces. In Study 5, women were slower to categorise rape-related stimuli when fertile compared to nonfertile, while fertility did not influence categorisation of stimuli associated with robbery or consensual sex. In Studies 6 and 7, neither fear of crime nor perceived risk of victimisation differed in relation to fertility. Therefore, overall, the findings suggest fertility does not influence responses to threats in general, with some evidence that the mechanism is specific to situations with increased possibility of rape. However, hormonal influences on responses to risk appeared to manifest in visceral responses (e.g., physiology, attention, cognitive biases) rather than conscious feelings (e.g., fear).