A reader asked the following question: I'm interested in why some people like dating multiple people at a time and others only focus on one. Is it just for attention? Low self esteem? Or maybe it's survival of the fittest- don't stop on one until you're officially locked down?
As you’ve probably noticed, the expectation in most cultures and societies is for individuals to be romantically involved with only one person at a time. This probably stems from the fact that marriage (which is almost universally defined as a union of two people) is frequently promoted as the “ideal” relationship state we should all be striving for. As a result, it tends to be the exception rather than the rule that people report engaging in non-monogamy.
For those who get involved with multiple partners simultaneously, why do they do it? There could be any number of reasons. Some might do it because they just aren’t ready to commit to one person, while some just aren’t sure what they’re looking for. Others might be driven by narcissism, sexual compulsion, or a need for validation. I should also note that some individuals simply feel like they can love multiple people at the same time, a practice known as polyamory.
In terms of what the scientific research has to say, you were on to something when you mentioned “survival of the fittest.” The field of evolutionary psychology thinks it is a natural human tendency to desire multiple partners, particularly if you are a man. In fact, research from around the world has shown that men have significantly greater desire for “sexual variety” (i.e., having a lot of different partners) over the course of their lives than women.1
Why do men want to be with so many people? From an evolutionary perspective, one of our major motivations or instincts is to produce as many of our own genetic offspring as possible in order to ensure that our genes are carried on to future generations. However, because the act of producing a child is, undisputedly, simpler for men than it is for women, the sexes tend to approach the mating game very differently.2 For men, the evolutionary strategy that makes the most sense is to sleep with as many women as possible because this maximizes their odds of having a lot of babies. For women, though, sleeping around indiscriminately makes far less sense. Yes, it might increase the chances of her becoming pregnant, but keep in mind that having a child requires a significant investment on the mother’s part, not only in terms of the 9 month pregnancy, but also in terms of the resources required to ensure that child’s health and survival after birth. Women who keep getting impregnated by guys who fail to stick around and help out with the kids may find themselves at an evolutionary disadvantage because they have to provide for themselves and their children entirely on their own (which probably proved exceptionally challenging in the days of hunter-gathers). As a result, the best evolutionary strategy for women is usually to be selective and hold out for a partner who will be reliable.
Thus, to answer your question, there are a lot of reasons why someone might choose to date several people at the same time, but at least for men, the desire for multiple partners might stem from an evolutionary drive.
For more on evolutionary psychology in particular, see here.
1Schmitt, D., et al. (2003). Universal sex differences in the desire for sexual variety: Tests from 52 nations, 6 continents, and 13 islands. Journal of Personality and Social Psychology, 85, 85-104.
2Buss, D. M., & Schmitt, D. P. (1993). Sexual strategies theory: An evolutionary perspective on human mating. Psychological Review, 100, 204–232.
Dr. Justin Lehmiller - Science of Relationships articles | Website/CV
Dr. Lehmiller's research program focuses on how secrecy and stigmatization impact relationship quality and physical and psychological health. He also conducts research on commitment, sexuality, and safer-sex practices.