Since we're just talking out our asses here, I'll say there's evidence that exposure to porn at young ages increases respect for women. The "evidence" is me. I first found porn mags at age 8 or so, and lots more, including videos, by 14. I have since become an avid porn collector. Yet I am absolutely respectful of women and always have been. I am far more respectful of women than the men in some no-porn areas I've lived in other countries.
Or maybe it's largely unconnected to porn. Maybe it's about culture and upbringing. In fact, there actually _is_ evidence that porn reduces rape (the ultimate form of disrespect for women):
And even though I'd still argue against allowing younger people's free access porn, the data in that article, tracking total internet usage, certainly includes young people's access to porn.