magazine issue 10 2007 / Issue 5

‘Forever and a Day’ or ‘Just One Night’? On Adaptive Functions of Long-Term and Short-Term Romantic Relationships

• written by Liga Klavina

Having grown up with such screen plots, we often wonder why our own love-path resembles more an awkward stumbling through the confusing mating and dating labyrinths with dead-ends and wrong exits taken. The mismatch between fairy tale scenario and real life set-up can be especially painful for women, who are since early age exposed to the image of the extremely handsome prince on a white horse, who is wealthy, athletic, and sufficiently witty to challenge severe obstacles to win her heart, and, moreover, inhibiting all potential desires to hurry to other princesses whose hearts could be conquered. Many young boys grow up believing in finding a gorgeous young woman, who would turn a blind eye to other outstanding men, and give birth to his, and only his, sons and daughters. Keeping all the ‘prince-and-princess-forever-together’ stories in mind, any break-up can be heart-breaking as you realize that he or she was not 'The One' and that all this time and investment is down the drain.

The ironic part in this is that for many people investing in maintaining a life-long committed relationship may not even be the most beneficial strategy, at least not during their entire lifetime. Now consider this storyline, which is far from a fairy tale, but close to reality. A young guy, let's call him Damien, is following an intense Spanish language class. In the socializing event after the first class he gets to talk to a young student – Mary. Damian is not the most ambitious and wealthy young man neither is he looking for a long-term partner with whom to settle down, and he is probably too adventurous and irresponsible to be considered a good potential father. Yet, he is a very good-looking, tall, and athletic guy, with masculine facial features, smooth skin, shiny hair and broad shoulders. He just seems so healthy, vibrant, and full of energy, that it does not go unnoticed by women. Despite the fact that Mary’s family is encouraging her to look for a guy that would be at least serious “boyfriend-material”, and preferably, “husband-material”, she is very attracted to Damian. They engage in a passionate relationship during the few weeks that the course takes place, but once out of sight, they do not pursue seeing each other. This is in an example of short-term mating and the trade-offs people are willing to make.

Are we evolved to be monogamous or polygamous?

The evidence is controversial. Some reports indicate that most marriages in preindustrial cultures are socially monogamous; whereas others show evidence for polygamous mating systems (see Schmidt, 2005). The evidence that humans possess neurophysiological system of pair-bonding and attachment (Hazan & Zeifman, 1999) speaks for the argument of human monogamy. However, there is abundant evidence that men with high status have multiple partners and higher reproductive success in foraging societies and across cultures (Betzig, 1986). Just like other polygamous primates, human males compete for mates and can be physically aggressive; and females benefit from genetically fit short-term mates, as it increases the fitness of their offspring.

Evidence of short-term mating existence in humans is cross-cultural – infidelity, poaching, cuckoldry, sex-specific jealousy, premarital sex are prevalent (Buunk, Angleitner, Oubaid, & Buss, 1996). Besides, like other short-term oriented primates, humans have moderate sexual dimorphism and secondary sexual characteristics and engage in non-conceptive sex.

Evidence from different domains is pointing to the fact that humans have evolved different mating strategies, and are able to functionally adjust mating strategies depending on individual characteristics and environment. As summarized by Gangestad and Simpson (2000), humans have been facing trade-offs between effort investing in parenting and mating and have evolved pluralistic mating strategies (e.g. men with less genetic benefits to the offspring may invest more in parenting effort than mating effort).

Why do we have adaptations for short-term and long-term mating strategies?

The ovulation of women is hidden, which is a source of parental uncertainty for men resulting in risk of investing in another man’s offspring. Thus for men mate-guarding becomes important and thus they tend to be more concerned about sexual infidelity. Men, relative to women, find it harder to forgive and are more likely to terminate a current relationship after sexual infidelity than an emotional infidelity (Schakelford, Buss, Bennett, 2002).