How real is the 'eldest daughter syndrome'? New science has answers

Are you the oldest sister in your family? Do you often find yourself taking on more responsibility than your siblings? You might be experiencing what's colloquially known as "eldest daughter syndrome".

But is this just a cultural stereotype, or could there be some scientific basis behind it?

A recent study led by researchers at University of California (UCLA) suggests there might be more to it than meets the eye.

The study: Stress, pregnancy and maturation

According to the UCLA-led research team, stress during pregnancy can have lasting effects on children, particularly first-born daughters.

Their 15-year longitudinal study, published in the February issue of Psychoneuroendocrinology, found a correlation between prenatal stress and early signs of adrenal puberty in first-born daughters.

Unlike boys or daughters who weren't first-born, these girls showed earlier patterns of adrenal puberty, marked by changes like the growth of body hair and aspects of cognitive maturation.

This finding sheds light on the concept of fetal programming, which explores how stress and other factors during pregnancy can impact children long after birth.

Evolutionary perspective: A deeper dive

Anthropologist Molly Fox, who led the study, suggests an evolutionary perspective to understand these findings. First-born daughters may mature earlier, not necessarily in terms of menstruation, but in cognitive and physical aspects, enabling them to assist in caring for younger siblings.

This insight challenges the notion that eldest daughter syndrome is merely a social construct. Instead, it suggests that there could be biological reasons behind the tendency of first-born daughters to take on more caregiving responsibilities within their families.

Research methodology: From pregnancy to puberty

The study recruited participants from obstetric clinics in Southern California, measuring maternal stress levels throughout pregnancy and postpartum. Children's adrenal and gonadal puberty biomarkers were assessed at different stages of development alongside measures of childhood adversity.

Through saliva samples and psychological assessments, researchers tracked the impact of prenatal stress on children's maturation. This comprehensive approach allowed them to tease out the specific effects of prenatal stress on first-born daughters' development.

Implications and future directions

Understanding the impact of prenatal stress on children's development is crucial for designing interventions and policies that support maternal and child health. By recognising the role of prenatal factors in shaping children's outcomes, we can work towards greater access to healthcare and improved well-being for pregnant mothers.

Beyond stereotypes

So, is eldest daughter syndrome a real thing?

While it may have a basis in both social and biological factors, studies like the one conducted by the UCLA-led research team provide compelling evidence that prenatal stress can influence children's development in significant ways.

As we continue to unravel the mysteries of foetal programming and its implications for maternal and child health, it's essential to move beyond stereotypes and explore the complex interplay of genetic, environmental, and social factors that shape who we are.

And if you're the eldest daughter feeling the weight of responsibility, know that you're not alone—and that science is beginning to understand why.

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This article was first published in theAsianparent.