Researchers from the Illinois State University in Normal have shown that the oft-cited adage Why keep the cow if you can get the milk for free? is little more than an old wives' tale. Writing in <a href="http://story.news.yahoo.com/news?tmpl=story&u=/nm/20021104/hl_nm/sex_relationship_dc_1">The Journal of Sex Research</a>, they explained their discovery that couples which enjoyed great sex were likely to experience a blossoming in their relationship; in contrast, couples which suffered unimpressive sex were liable to experience dissatisfaction in other aspects of their relationship, and as such were more likely to break up. This counterintuitive link between orgasms and emotions is actually quite easy to explain. Contrary to popular belief, it isn't easy for people to find compatible sex partners, much less enjoyable sex partners. In view of this, it isn't surprising that good sex can become the foundation of a solid relationship. After all, once you've found a cow offering deliciously creamy milk, you'll want to keep it!