The internet is filled with tales, anecdotes and reports on birth order and the supposed role that our position within the nuclear family plays in our lives.
From successful first-born leaders, to rebellious middle-borns. From the ever-babied youngest to the mature, possibly lonely, only child - no matter what the family dynamic, someone, somewhere, seems to have something to say about it.
As a mum of seven, where the middle child position has proven an ever moveable feast, I often wondered if the place my children hold within our family is likely to have any effect on the adults they grow up to be, or indeed the very individual children that they currently are.
Is it possible that there might be something to these stereotypes? Or could they prove to be a self-fulfilling prophecy, in the same way our horoscopes can when we bump into that "mysterious stranger" at the local shop while picking up milk?
Joanna Fortune, clinical psychotherapist at Solamh, believes that, during adulthood at least, a lot of this is based on whether or not you believe it is true.
"If you think it's true, then you're going to live accordingly, whereas if you believe, 'that's not who I am', you won't live like that."
During childhood, however, birth order can potentially have a big effect on personality formation.
"The first-born child often has quite a tough order," she says. "Parents are new - firstborn means first parents. The stereotypical firstborn is seen as reliable, conscientious, cautious, controlling, and high-achieving, and a lot of expectation can be put on them. They may strive to be the best at everything they do and often have their achievements validated by all the family."
Conversely, last-borns are thought to be disinhibited, fun-loving and outgoing because of the lack of pressure and more chilled out parents.
As for only children, Joanna believes that a lot of myths surround them, with inconsistent research. "What is different with single children is the parenting experience. Siblings toughen each other up. They have to develop skills to cope with each other."
Contrarily, the formation of a single child's personality is down to "how they are parented".
"Single children have a tendency to be mature for their age, partly because they are around adults so much," she adds.
It can, however, "often be a pseudo-maturity".
They can be "perfectionists who like things done a certain way because that hasn't been challenged at home in their play experiences. They have never painstakingly built a tower and had a younger sibling come in and kick it over."
By contrast, middle children "have a name for being people-pleasers. They can be rebellious and attention-seeking. They can also manifest as peacemakers".
"Middle children are symptomatic of parents taking their foot off the gas a little," she adds. "A more relaxed approach to parenting sees different personality traits come up."
Unconvinced of middle child syndrome's existence, Joanna feels that the age gap between the middle child and the child above proves more influential than birth position. "If you have a middle sibling but the older child is four, five, six years or more, it's a lot like you're starting over. Those children aren't in competition developmentally with each other.
"However, if you've got a child where the age gap is two, maybe three years, you will have sibling rivalry because, developmentally, they're competing, and that's unavoidable."
We all assume roles in our family, she adds, but this is not necessarily decreed by birth order.
"It's about parenting responses and how we parent each child in birth order," says Joanna, "rather than birth order deciding how we parent.
"Remember, you are parenting individuals and not a herd. And when it comes to discipline and boundaries, what's effective with one child might be completely useless with another. Your parenting style might have to adapt to the personality and needs of each child.
"If your eldest child is that classic achiever type, manage your expectations of your middle child because they may have different measures of success. Focus much more on praising each child's effort rather than the outcome.
"And if you're parenting a single child, don't beat yourself up that you've somehow denied them something because they don't have a sibling. Take a bit of pressure off the child. Give them time to play alone. Intricate playdates every other day to compensate for the fact that they don't have a sibling are unnecessary. That's actually an adult projection, not a child need."
In spite of all this generalisation, Joanna is keen to emphasise that these traits and personalities aren't fixed. "Children will have other life experiences and come into contact with other people who influence these behaviour traits."
So how does all of this fit alongside my own children, whose roles have evolved over time?
Joanna believes that when speaking about the birth order of children, you have to start with the birth order of the parents.
I am the eldest so apparently likely to be particular about how things are done. I don't want my parenting judged and hold myself to very high standards. On the other hand, youngest child parents tend to take a much more relaxed approach.
My eldest child, a girl, is 15, and similar in personality to me. As a kind, mature, capable, responsible girl, she is viewed by the children closest in age to her as their equal, while the younger children see her almost as an adult, a worthy advisor and person to offer comfort in my absence.
Joanna says this is unsurprising and my daughter "must believe this, as she embodies it".
"If she took the view, 'I don't care what you do' with her siblings, they wouldn't see her as a leader."
Child two is 12. He's gentle, kind and sensitive by nature. And laidback - oh so very laidback. Joanna says the second child has a tendency to be a little bit more chilled out and may be happy to defer to the eldest, things that he could do himself.
Child three is 10. He's an almost middle child who is very comfortable in his own skin and doesn't subscribe to herd mentality. He has a strong family attachment and is brilliant with his younger siblings.
Stubborn might be used to describe him sometimes. Joanna feels the description suggests he has a lot of youngest child attributes in spite of having four younger siblings. She puts this down to the spacing due to our family size, which "effectively creates two separate birth orders".
According to Joanna, because of the large family variable, I can expect child three to be quite a mixed bag - someone who'll keep me on my toes. "He won't fit neatly into any birth category as he doesn't have a natural birth order slot."
Child four is my actual middle child and I know, before I describe my seven-year-old son, that there is no sign of middle child syndrome here.
He is articulate, competitive, caring, mature and a perfectionist. Joanna explains that he fits more into the category of "stereotypical eldest child" and that, within our family, he possibly sees himself as "an eldest child of the second batch". I witness him more as a child trying to hang on to the coattails of the eldest lot.
Child five is my self-proclaimed "favourite child". At five years of age, he is quirky, precise, fair and lots of fun. We view him as the eldest of our youngest. A combination of eldest and youngest child traits are what Joanna says I can expect, and the fact that he could take on the position of "youngest of the eldest" might explain his conviction that he's the favourite.
Child six is my threenager - determined, independent, extremely capable and confident. As the middle child of our youngest children, he would challenge the authority of any of his brothers but accept his sister as being in charge. They share a birthday and are very close. Joanna explains that his "maternal relationship with his sister" is the reason he doesn't challenge her. His place in the birth order means he's likely to get away with "quite a lot of things that the older children didn't".
And finally child number seven, my one-year-old baby, adored by the entire family. At any given moment he has six siblings who are willing to stand on their heads to make him smile. He is happy, affectionate, relaxed, surprisingly gentle and sociable. With so many people validating his every effort, Joanna believes he will be a "quietly confident, relaxed child who makes it all look easy".
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