I’ll have what she’s having

More and more Australians are meeting their partners online. A 2011 worldwide study of 25,000 married or cohabitating people found that 15% of all relationships started online. In the group who were 60 years-plus, 37% had met their partners through the internet. According to a 2013 report, over half of Australians have tried online dating or consider it a viable option to meet a partner.

In venturing into the world of online dating, some individuals consider methods to optimise their chances of finding a suitable mate. Here self-promotion is the paramount in standing out from the crowd. Perhaps paradoxically, highlighting your previous relationship history to prospective partners may have a positive impact on securing a date.

Mate copying is the theory that an individual's decision to mate or form a relationship with a potential partner is impacted by observation of that person in a relationship with another, or knowledge of their romantic history. This phenomenon has been extensively documented in non-humans. In the last decade evidence has emerged to support the existence of mate copying in humans. While it was traditionally assumed that women chose their prospective partners independently, evidence now suggests that the choices of other women may influence their decisions about whom they choose as a romantic partner.

The idea behind mate copying is information gain. Why go to the trouble of collecting data for yourself when you can let someone else do it and get it for free or at a heavily discounted price? Acquiring information this way may sound ethically questionable, but is it immoral to pay less for something than someone else, or behave in a way that is economical, rational, or clever?

Imitation is a fundamental behaviour of human existence and evident in many domains of life. People copy fashion styles, culinary preferences and business strategies. This is considered perfectly normal and in some cases essential. Utilising the choice-information of others to guide decisions makes sense, especially when the alternative is a time and resource consuming trial-and-error approach, or the risks of making the wrong decision are significant. In terms of relationships, if Sarah 'recommends' John (as evidenced by her romantic association with him), maybe John is 'valuable' enough to go out with. If Sarah is particularly attractive (an appealing characteristic) surely there must be something about John that Sarah found appealing. Why did she choose John over her (presumably) many other suitors? A woman considering whether or not to date John would do well to at least pay attention to this information.

In many of the studies of mate copying to date, researchers have focused on females only. This reflects the fact that mate selection in humans is predominantly at the discretion of females. Qualities sought by females in a mate (such as sociability, dominance, parental ability etc.) may be particularly difficult to readily discern.Is a man going to be faithful? Is he going to be a good provider? Is he going to make a good father? These are difficult questions to answer. A mate-seeker would be well advised to take into account as much information as possible. The problem for men is different, and largely centres around characteristics that are easily observable (smooth skin/lips, lustrous hair, spritely gait etc.). The need for additional information is not as great.

In studies where women are asked to rate the attractiveness of photographs of men with a female partner versus alone, men pictured with a partner are considered to be more attractive. This finding has been replicated in studies where participants view speed dating footage. Controlling for individual characteristics, men perceived to be more successful at the process were favoured over those that were not. This general finding does not hold regardless of age though. It appears that younger females may be more susceptible to mate copying, following the lead of older females.

A caveat to these findings is that mate copying appears to only occur if the male's previous female partner is considered attractive. In other words, men are considered more attractive only if their previous partner is regarded as beautiful.

Another important qualifier is that while having a previous partner appears to increase the attractiveness of a man, having too many partners is considered undesirable. In a recent study, men with one or two ex-partners were considered very attractive. However, men with five or more ex-partners were considered highly unattractive. While having a previous relationship signifies the presence of desirable traits, having a significantly large number of previous relationships sends messages of promiscuity and lack of commitment.

In the United States, there exist companies that create the illusion that men have women interested in them (so called "wing-women" services). In Australia, consumers are becoming increasingly comfortable with spending on dating services, in particular online dating services.

On the topic of human relationships, the famous Czech writer Milan Kundera mused, "[it is] one of life's great secrets: women don't look for handsome men, they look for men with beautiful women". Here we present evidence for this assertion.