Searching pubmed for the term "hooking up" reveals the following (sex-related) articles:
First mention was in 2003 in the Journal of Sex Research, and the most interesting paper by far: "both women and men rated their peers as being more comfortable engaging in these behaviors than they rated themselves. Men expressed more comfort than did women in engaging in these behaviors, and both sexes overestimated the other gender s comfort with hooking up behaviors."
Second mention: 2007, in J Interpersonal Violence about unwanted sexual experiences while hooking up.
2008: 3 mentions.
1. Hookups more likely among extraversion and less likely among low conscientious. [Note: this puts some context behind qualitative study of Bogle that women perceived all "dateable" men as interested only in hooking up: these women may view only high extraversion and low conscientious as dateable, while the low extraversion and high conscientious may have been considered less dateable.]
2. Oral sex seems not to be regretted, just vaginal sex, and especially with a one-time-only encounter or with someone met in last 24 hours.
3. More likely among higher income, white, alcohol users; women less positive reactions.
2009: 3 mentions.
1. The first longitudinal study looking for predictors of hookups (measured in the second wave), but nothing surprising: alcohol, high school hook-ups predict college hookups. Any sex in hookups associated with psychological distress for women but not men.
2. Qualitative study: men also have feelings about casual sex, not all positive, and not all no-strings-attached.
3. Hookups may have higher than normal STI risk, and may undermine sexual self-efficacy.
Interesting to find that there are only 8 articles that turn up. Obviously casual sex is more common in the literature, but the phenomenon of "hooking up" may be more widespread or normative than past casual sex. Certainly the first paper, about students' own attitudes towards casual sex being more ambivalent than their perceptions of their peers' beliefs, may not have been true a few decades ago.