'Eldest daughter syndrome' in families is actually a thing, according to science

Science has proved that the theory of the 'eldest daughter syndrome' holds up, and for a number of factors.

'Eldest daughter syndrome' may sound like a social media trend, or something made up by those who fit into the category, but a study has concluded that it's actually a real thing that could even be an issue.

The psychological concept centres around, that's right, female first-born children and their behaviours or mannerisms that make them so different to their siblings.

It shows how they experience parentification early on in their lives, meaning that they feel some responsibility to help to take care of their siblings and to start helping out around the household.

Almost made to be an example for younger siblings, they are thrust into becoming role models to them.

The syndrome looks at the physical and mental effects of basically fast-tracking through childhood to become a grown-up sooner than planned.

Eldest daughter syndrome is not technically a physical diagnosis, but a new study may have taken a step in that direction, as it uncovers some reasons why it may proves to be so relatable to several women today.

A research team from the University of California have discovered that first-born daughters in general mature earlier than other siblings.

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This puts them into the mindset of being the caretaker for their younger siblings.

Basically, it has to do with Adrenal puberty, which is marked by physical changes like acne or body hair, as well as mental changes such as emotionally maturing.

Though, this is different to regular puberty, which brings on aspects such as breast development and menstruation.

The team found a direct correlation between the early signs of adrenal puberty in first-born daughters and mothers having high levels of prenatal stress.

Jennifer Hahn-Holbrook, assistant professor of psychology at the University of California, Merced, and one of the co-authors of the study, revealed that when mothers get stressed during pregnancy, their eldest daughters maturing quickly will benefit them.

She explains: "It gives Mom a ‘helper at the nest’ sooner, aiding the women in keeping the latter offspring alive in difficult environments."

The study's findings highlighted that girls would become mentally capable enough to care for their siblings in the same way parents would, without having the children herself.

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Results were published in the February 2024 issue of Psychoneuroendocrinology, which involved the researchers recruiting women from obstetric clinics in Southern California and gathering information during first-trimester prenatal care visits.

What was found was that it was the first pregnancy for half the mothers, and they steered clear of tobacco, alcohol, drugs, and were non-smokers.

Depression and anxiety levels were monitored during pregnancy for the mothers, and when the children were born, some aspects of their adrenal puberty were assessed.

Eldest girls matured the fastest when mothers experienced high levels of prenatal stress, in contrast to eldest sons or daughters who weren't first-borns.

Hahn-Holbrook further revealed: “One reason that we didn’t find this effect in first-born children who are sons could be that male children help less often with direct childcare than female children do, so mothers have less of an adaptive incentive to speed their social pubertal development.”

She concluded that previous research on the subject implied that female puberty timing is more easily influenced by early life experiences, compared to males.