Earlier quoted context omitted.
Start here: http://www.crosswalk.com/news/commentary/11601061/ It's the first cite I found, but if that's not religion-neutral enough for you, I can find plenty more. Sex causes the release of hormones such as oxytocin. Most people aren't capable, especially when young, of having sex with someone, never seeing that person again, and being okay with the experience.
if that's not religion-neutral enough for you crosswalk.com - "Your gateway to the bible and christian resources"
http://www.dailymail.co.uk/femail/article-1031259/Casual-sex...
I can keep doing this, you know, given the enormous amount of research that's on my side.