Scientists have revealed that a person's birth order directly influences their dating choices.
The theory stems from the idea that birth order shapes who you are, influencing your personality traits and relationship dynamics.
The core idea is that opposites attract. In other words, people look for partners whose birth order compliments their own, explained Licensed marriage counselor and family therapist.
For example, eldest daughters and youngest sons tend to have opposing personality traits, which makes them more compatible. Wright herself is an eldest daughter married to a youngest son, so she can attest to this.
Understanding what your birth order says about you can even help you 'predict' who you'll be attracted to.
Science suggests that a person's birth order has a big influence on the type of romantic partner they look for.
'In my experience professionally, and personally as a firstborn, firstborns typically receive more attention and resources from parents,' Annie Wright, a licensed marriage and family therapist, told Business Insider.
'It can lead to higher academic achievement, greater leadership qualities, and a more conscientious nature.'
Youngest siblings, on the other hand, 'tend to develop a more sociable and accommodating personality,' she said, because parents typically take a more relaxed approach to raising their youngest children.
Because of this, eldest siblings and youngest siblings make a complimentary romantic match, wherein the firstborn is naturally inclined to take charge while the youngest sibling is happy to cooperate.
Dating someone with the same birth order as you, however, can lead to disaster. For example, two first-borns may fight over who gets to be in control at certain points in a relationship.
On the other hand, two younger-borns could struggle to find structure and allocate responsibilities in a relationship.
The theory isn't as clear-cut for only children or middle children, who may relate to both eldest-born and youngest-born traits.
But there are some traits that tend to be common specifically in only children and middle children, and these people might look for a partner who compliments these aspects of their personalities.
Middle children, for instance, tend to be highly adaptable and good at compromising. Therefore, they might pair well with first borns.
Only children are often sensible, conscientious and independent, so they tend to pair well with last-borns.
The birth order dating theory has created quite a buzz on social media, with many people on TikTok and Instagram confirming that their own dating history supports the theory.
'I am the eldest daughter, and all of my relationships have been with the youngest sons,' one TikTok user said.
'My mind is blown,' she added.
But the birth order dating theory isn't a steadfast rule. At the end of the day, each relationship is unique and can't be defined assumptions about what makes two people compatible.
'We can't speak in absolutes, whether it's talking about who you are because of your astrological sign or who you are because of your birth order,' Wright said.