Study author Susan Hughes, associate professor of psychology at Albright College in Reading, Pa., says most research on sex focuses on what leads to sex, but a number of elements of reproduction happen after sexual intercourse, including: bonding, future relationship intentions and possible continued sexual activities, sperm retention and competition, mate guarding and the possibility of fertilization.
Hughes says the study, to appear in the upcoming issue of The Journal of Sex Research, involved 170 men and women who completed a questionnaire.
The study found women were more likely than men to initiate and place greater importance on behaviors linked to intimacy and bonding with both long and short-term partners. Men, on the other hand, were more likely to engage in extrinsically rewarding tasks such as smoking, asking for a favor or behaviors that increased the odds of having sex again. Men also initiate having more sex.
Both men and women agree on the importance of saying "I love you" to a long-term partner after sex, Hughes says.