Oldest Siblings Most Likely To Cheat, Says New Study

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oldest sibling cheating

A new Ashley Madison study suggests that a certain sibling is more likely to cheat than others.

Does birth order have anything to do with cheating? Yes, it seems so. Ask any scorned lover and they’ll swear up and down they’ve got a sixth sense when it comes to cheaters, that they can pick the unfaithful out of a crowd based on a person’s hairstyle alone. While this might certainly be a special talent, there’s likely no actual science behind it.

However, there is now a new (sort of sciencey) study that could aid us in being able to spot a cheater, and it comes from the romantically progressive labs of Ashley Madison. According to a new study by the world’s leading “married dating website,” there is evidence that the eldest sibling might be the most likely to step outside of the perimeters of monogamy. (Insert the sighs of relief from second and middle children everywhere here). 

In the study, 1000 Ashley Madison members were surveyed. Of those 1000 members, who have all already implicated themselves as cheaters (so they’ve got no reason to sugar coat their responses), 78% have siblings.

Of that 78%, a whopping 40% were the eldest sibling, therefore tarnishing their squeaky clean images as the prodigy children. Furthermore, the most prevalent group of those who were most likely to cheat had two younger siblings, at 31%. And following closely behind are those who have only one sibling, at 26%.

RELATED: How Your Birth Order Affects Your Personality (It's Fascinating!)

So what gives? Why are the eldest siblings, who are most often associated with leadership and success, being linked so closely with infidelity? Which, in many societal norms, is a black streak on an otherwise shining reputation.

Well, ask any person who is  the eldest sibling, and they’ll most likely tell you that they feel they’re put under a much brighter (and some might say “harsher”) parental spotlight than their brothers and sisters.

Since they were the only child in the family to have received uninterrupted one-on-one time, the expectations are higher, and therefore, the stress of meeting those expectations is as well.

On the other hand, other studies have indicated that the eldest are also more likely to experience more success in their careers due to their birth order, and being born into the natural position of leadership among their brothers and sisters.

“The oldest sibling is notably known for being a leader and having a competitive nature,” says Isabella Mise, Director of Communications for Ashley Madison. “It may be that take charge personality that leads them to ultimately take control of their sex life and get their needs met.”

RELATED: Who You're Most Compatible With, Based On Your Birth Order


More money, more problems? Possibly, but regardless of wealth, it seems like being the eldest is both a blessing and a curse.

Not that this news equates to imminent doom for those who are romantically involved with someone who happens to be the first born, but there are a few famous faces whose actions can vouch for Ashley Madison’s statistics. Take Vanderpump Rules’ serial cheater, Jax Taylor, for example — he’s the eldest of two, and his younger sister, Jenny, just got engaged last December.

Then there’s Brad Pitt, who wore an infamous scarlet letter after cheating on his then wife, Jennifer Anniston, with his co-star from Mr. & Mrs. Smith, Angelina Jolie. Pitt happens to be the eldest of three — he’s got a younger brother and sister, Doug and Julie.

What might be the most worrisome aspect of this study is not the famous faces who can back it up, but the fact that 86% of respondents reported having had a happy childhood. So the age-old historic indicators like “Daddy took off and Momma drank all day” are not to blame when the eldest sibling strays, at least not in this survey.


These respondents also reported having close relationships with their younger siblings, though 81% of them would never admit their infidelity to their brothers or sisters. Perhaps sibling rivalries play a role in their secrecy—the eldest, after all, is synonymous with being the apple of their parents’ eyes.

Hell, maybe it’s that classic sibling rivalry that is to blame for this entire batch of statistics.

Historically, the eldest has to have it all, the middle child just wants someone to remember their damn birthday, and the youngest is on a constant search for new boundaries to cross and rules to break, because their parents are too preoccupied with singing the eldest’s praises while also keeping the scorned middle child at bay to pay attention to the youngest‘s rebellion.

But I’m an only child, so though it pains me to say it, Ashley Madison might be the more trustworthy source in this case.

RELATED: How Your Birth Order And Zodiac Sign Can Influence Your Career Choices​

If you’ve got siblings, what do you think? Is the eldest keeping secrets to maintain their position as the prodigy child? Or is this just another study that’s going to give those who are in happy relationships another reason to sleep with one eye open (as if there aren't enough of those already)?

Hannah Murphy is a southern writer and mom of three (two human, one canine). She has a deep love of bacon, babies, dinosaurs and vodka—not always in that order. When not chasing her two boys and husband you can find her obsessively reorganizing her house, moonlighting as a medical professional, and yelling at the TV during football season.

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