New study reveals fresh evidence for ‘eldest daughter syndrome’

Over the last few years, many people have been turning to social media to discuss a psychological concept known as eldest daughter syndrome.

The concept is centred around signs that female first-born children tend to experience parentification in families early on, becoming a caretaker for their younger siblings and picking up extra domestic labour. These children are often expected to set an example for their younger siblings, taking on more responsibilities and acting as role models. The syndrome deals with the physical and mental ramifications of needing to grow up so fast.

Although the phenomenon is not listed as a physical diagnosis, a new study has revealed fresh evidence pointing to why eldest daughter syndrome is proving a relatable notion for many first-born women.

A University of California, Los Angeles-led research team recently discovered that first-born daughters tend to mature earlier than normal, which would put them in the proper headspace to fulfil the required caretaker role for their younger siblings.

The team specifically noticed a correlation between early signs of adrenal puberty in first-born daughters and their mothers having experienced high levels of prenatal stress.

Adrenal puberty is marked by both physical changes, such as growing body hair and acne, in addition to mental changes when people gain emotional maturity. Adrenal puberty does not include certain aspects of traditional puberty such as breast development and menstruation.

When times are tough and mothers are stressed in pregnancy, it’s in the mother’s adaptive best interest for her daughter to socially mature at a quicker pace, said Jennifer Hahn-Holbrook, one of the co-authors of the study and an assistant professor of psychology at the University of California, Merced.

“It gives Mom a ‘helper at the nest’ sooner, aiding the women in keeping the latter offspring alive in difficult environments,” she said.

The study explained that the girls become mentally capable enough to take care of their siblings the way a parent would, without being physically developed enough to have children of their own, which would naturally draw them away from their older-daughter responsibilities.

The results of this study, published in the February issue of Psychoneuroendocrinology, also involved the researchers recruiting women from two obstetric clinics in Southern California during routine first-trimester prenatal care visits.

For half of the mothers, it was their first pregnancy and they were non-smoking in addition to not using steroid medications, tobacco, alcohol or other recreational drugs.

Throughout their pregnancies, their depression and anxiety levels were measured and once the children were born, certain aspects of their adrenal puberty were also measured. It was found that the eldest girls matured the fastest when their mothers experienced high levels of prenatal stress.

The same cannot be said for eldest sons or daughters who are not first-born.

“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,” Hahn-Holbrook explained.

Plus, she said, previous research suggests that female puberty timing is more malleable in response to early life experiences than that of males.