As it happens, there is not a shred of evidence in the research literature to support the theory that a woman's risk of suffering serious sexual assault is linked to her clothing. Many factors have been identified as putting a woman at statistically greater risk, including drinking, her consensual sexual habits and (tragically) her past victimisation, but you'll find nothing on clothing. What research there is on rapists and their decision-making points to the rapist's opportunity and the victim's vulnerability (psychological and situational) as the relevant factors, not appearance. Those who work on the frontline with rape victims testify that they come in all shapes, sizes and sartorial shades.
I'm a huge admirer of the SlutWalk movement, but it's disappointing it has only led us to this debate about the "I'm-all-right-Jill" approach to rape prevention, and has yet to progress to the bigger, better question of how we reduce the number of rapes happening in the first place?
The motivations, decision-making and psychopathology of rapists are complex and much disputed between and within disciplines. Human behaviours emerge from an intricate web of socialisation and learning, evolved instincts, neurobiology and those myriad traits and cognitions we call a personality. Much of that is hard to change (in adults at least) but not all.
Our actions are affected and altered by the prevailing attitudes and values surrounding us. For example, it was not criminalisation that radically reduced drink-driving in the UK, but changes to the social norms. Sexually abusive behaviour is on a continuum and it's surely not the case that there is a clear distinction between the thought patterns of well-adjusted people on one side and the twisted, perverted logic of the rapist on the other. Yes, there may always be sadistic sexual psychopaths and otherwise deranged offenders, but there also has to be a significant number of rapists who are, shall we say, borderline cases – unsure of themselves and their actions, perhaps shaken by self-doubt or fear.
It seems almost certain that some such men can be swayed not only by better education around issues of consent and sexual violence, but also by the attitudes and values of their friends and family around them, and the voices in the pub, workplace and media. All these provide hints as to the degree of social acceptability or perceived evil of their behaviour.
That is why it is vital to challenge and rebuke remarks that trivialise or normalise rape, whether made by an internet troll or the UK justice secretary. That is why it is always dangerous to dehumanise women by comparing their bodies and sexual integrity to property and possessions, and that is why it is reprehensible to suggest that a woman in a sexy skirt should expect to be raped.