A new study finds that “eldest daughter syndrome” is real, so call your sister and let her know

As the eldest sibling, writer YL Wolfe often felt the lines between his role and that of his mother were blurred.

“When I was almost 11, my youngest brother was born and I felt a sense of responsibility for his welfare. I would often sit next to his crib and watch him sleep, just to make sure he was safe.

“It’s not that I don’t think my mother is capable, it’s that I think we are capable Both By then I was responsible for the family,” she explained. “It’s like I’m really ‘another mom’ instead of a big sister.”

In other words, Wolff is very familiar with “eldest daughter syndrome”. The internet is awash with musings on the plight of older daughters, and tweets about how we—I might as well reveal my bias here—need to unionize: “If you’re the oldest sibling who’s also a girl, you might entitled to financial compensation,” One woman joked on X, The platform was formerly known as Twitter.

While “eldest daughter syndrome” is a popular psychological term—you won’t find it listed as a formal diagnosis in the DSM-V—a new study suggests this pseudo-syndrome may be more common than previously thought. science.

A UCLA-led research team has found that in some cases, eldest daughters tend to mature earlier, allowing them to help their mothers raise younger siblings.

Specifically, the researchers found a correlation between first-born daughters showing early signs of adrenal puberty and their mothers experiencing high levels of prenatal stress.

Why does the age of adrenal puberty matter? Changes to the skin (such as acne) and body hair occur during this stage, but so do changes in brain development. The adrenal puberty process is thought to promote social and cognitive changes; essentially, superficial physical changes related to emotional maturity.

Jennifer Hahn-Holbrook says that when times are tough and mothers are stressed during pregnancy, it’s in a mother’s adaptive best interest to have her daughter mature more quickly in society. co-author of the study and an assistant professor of psychology at the University of California, Merced.

“It provides mothers with ‘helpers in the nest’ more quickly, helping females keep their offspring alive in difficult circumstances,” she said.

It’s important to note that adrenal puberty does not include breast development or the onset of menstruation in girls (or testicular enlargement in boys). Research suggests that girls are mentally mature enough to take care of younger siblings but are physically incapable of bearing children of their own, which naturally frees them from responsibility for their eldest daughters.

When it comes to this kind of parentification, older brothers seem to be off the hook: The researchers didn’t find the same results in boys or girls who weren’t the firstborn.

“One reason why we did not find this effect in first-born sons may be that boys have less help with direct childcare than girls and therefore have adaptive incentives for mothers to accelerate their social pubertal development. Less,” Hahn-Holbrook explained.

Additionally, she said, previous research has shown that the timing of puberty in women is more affected by early life experiences than in men.

The study’s results are published in the February 2024 issue of Psychoneuroendocrinology (it’s said to be five times faster, or just once) It was a long process: The researchers followed the families for 15 years , from the pregnancy stage to the baby’s teenage years.

The researchers recruited women from two obstetrics clinics in Southern California for routine early prenatal care. The women were on average 30 years old and were carrying children, not twins.

For about half of the participants, this was their first pregnancy. These women did not smoke or use steroid medications, tobacco, alcohol, or other recreational drugs during pregnancy. They are all over 18 years old.

Women’s stress, depression and anxiety levels were measured at five different stages of pregnancy and then measured cumulatively. The depression assessment asked women to rate the truthfulness of statements such as “I feel lonely,” while the anxiety questions asked how often they felt specific symptoms, such as “nervous.”

Of the children born to these mothers, 48% were female and 52% were male.

Adrenal and gonadal pubertal characteristics are measured separately as children get older – such as body hair, skin changes, height gain or growth spurt, breast development and onset of menstruation in women, and voice changes and facial hair growth in men.

The study also measured childhood adversity to account for other factors known to be associated with early puberty or signs of puberty in children, such as the death of a parent or divorce before age 5, as well as father’s absence and financial uncertainty between ages 7-9.

Taking all of this into consideration, the oldest girls mature the fastest when their mothers experience high levels of prenatal stress.

Other research suggests that highly responsible older daughters reap some rewards later in life: A 2014 study found that of all sibling types, eldest daughters were most likely to succeed, while a 2012 study found that eldest daughters It is easier to achieve success.

This finding rings true for Wolfe, the aforementioned author, who said she felt like a second mother to her siblings while they were growing up.

“I’m not surprised at all by this study’s findings,” Wolf said. “My story is slightly different – I experienced true puberty at age 12, not just adrenal puberty, although I suspect I experienced early cognitive maturation.”

The study is interesting for another reason: The findings add to social scientists’ understanding of fetal programming, an interesting area of ​​research that explores how stress and other emotional and environmental factors women experience during pregnancy influence the birth of a child. After a long time.

“This is an unprecedented discovery that is interesting from an evolutionary perspective,” UCLA anthropologist Molly Fox, one of the study’s co-authors, said in a press release.

In an interview with The Huffington Post, Fox went deeper into how fetal programming works.

“An interesting theory is that when you are a fetus in your mother’s womb, you get clues about what the world is going to be like, and your body can flexibly adjust the shape of your life cycle to best suit Things you expect to encounter,” she said.

Fox and her co-authors are pleased that their work is available for the public to read, especially after following these families for so long. The fact that the findings come at a time when a cultural conversation about older daughters is erupting is just icing on the cake, especially for Fox, who is also an eldest daughter. (She is a twin.)

“As the oldest child, I think that’s a special role in any family because it allows me to be close to my mother and have the ability to help take care of my younger siblings,” she said.

Spoken like a real eldest daughter. This article was originally published in Huffington Post.