Ever wonder why one partner for life just feels right for some people, while others find it an incredibly difficult standard to uphold? Well, counter to what many believe, that may have more to do with nature than nurture.
There has been a lot of talk lately about millennials’ proclivity toward casual sex and open relationships, but not a lot of hard, scientific evidence to back it up. And while this new study does provide some insight into our sexual nature as mammals, it doesn’t necessarily make the debate over generational dating habits any more cut and dry.
A study conducted by the University of Texas in Austin and published in Science last week suggests that monogamy could be a genetic predisposition. Researchers looked specifically at the mating habits of prairie voles because they are a species known for its monogamous tendencies. Yet while on the whole male and female prairie voles pick one mate with which to raise their offspring, some males opt for the bachelor life, getting busy with multiple female partners.
According to the researchers, these philandering voles are just as much a part of natural selection as the monogamous ones are. “This brain variation isn’t just there by chance. It isn’t random,” Steven Phelps, associate professor of integrative biology and the lead investigator on the study, told Science Daily. “It’s actually something that selection has kept around for a very long time. When it comes to social behavior, maybe there isn’t a normal brain.”
The reason evolution has kept both the unfaithful and faithful male voles around is that both succeed in furthering the species. The unfaithful males impregnate more females, thereby increasing their number of offspring. However, while they’re off dallying with other lady voles, their primary mates may get impregnated by a different male vole, and once their philandering mate returns, he’ll end up raising babies he didn’t sire. Meanwhile, the faithful male voles know they’re raising their own offspring and thus have more of a care for them, but because they mate with only one female, they don’t have as many offspring.
And yes, there is a decided difference between the brains of the faithful and unfaithful voles. The researchers actually saw the distinction in the area of their DNA that is responsible for the genes that activate spatial memory. Essentially what this means is that the faithful males are able to remember they have a singular mate better than the voles genetically programmed to be unfaithful.
So does this mean that if your boyfriend cheats on you, it’s because he was born to do so? Not necessarily. Just because a mammal with similar mating tendencies exhibits this genetic difference doesn’t mean that’s the reality for all. It also doesn’t mean that the way in which someone was raised isn’t directly responsible for their sexual proclivities later in life. Many would argue that millennials’ attitudes toward casual sex and waiting longer to get married than generations before them is directly related to the higher divorce rates of their baby boomer parents. Thus you can see how this theory gets exponentially more complicated when you try to translate it into the human social construct.
The long and short of it is, the cheating voles are still around because they actually serve an evolutionary purpose. And while our society definitely doesn’t condone the same behavior, that doesn’t stop it from remaining a social constant. So regardless of whether our changing notion of partnering is genetic or environmentally related, it’s important to realize that there may be a larger reason behind the deviation.