'When teenagers fool around before they're ready or have a very casual attitude toward sex, they proceed toward adulthood with a lack of understanding about intimacy.'" Nationally, women now outnumber men in college enrollment by 4 to 3, leading some researchers to argue that the gender imbalance fosters a culture of hooking up because men, as the minority and limiting factor, hold more power in the sexual marketplace and use it to pursue their preference of casual sex over long-term relationships.
One study has found that the strongest predictor of hookup behavior was previous experience hooking up.
Most predictors among males and females rarely differ.
These developmental shifts, Garcia's systematic review of the literature suggests, is one of the factors driving the increase in hookups, a "popular cultural change that has infiltrated the lives of emerging adults throughout the Western world." The review shows that hookups are becoming increasingly normative among young adults and adolescents in North America and have taken root throughout the Western world, which represents a notable shift in how casual sex is perceived and accepted.
Garcia and others have noted that the "past decade has witnessed an explosion in interest in the topic of hookups, both scientifically and in the popular media.
During the twenty-first century paid sex was not considered to belong to the category of casual sex; however, in the 1900s-1930s there was more to paid sex than simply the exchange of money–it was a contact between humans without the ties of a relationship.
Technological advancements such as the automobile and movie theaters brought young couples out of their parents' homes, and out from their watchful eyes, giving them more freedom and more opportunity to engage in sexual activity.Hooking up leads to instant gratification for sex, pleasure, a feeling of being loved, an emotional feeling of being adhered to, the thought of the potential of the hook up developing into something less casual, and many more reasons.