The not-so-latent science nerd in me is super excited about some groundbreaking research from University of California San Francisco (UCSF) that is directly challenging everything we’ve been told about ageing in women and is providing compelling evidence against the narrative of cognitive decline after midlife.
The discovery reveals that women’s so-called “silent” X chromosome, previously thought to be largely inactive, AWAKENS around age 65 to provide significant cognitive advantages. This isn’t just fascinating genetics; it’s biological validation that women’s midlife may be the beginning, not the end, of our cognitive prime.
Women’s Midlife ‘X Factor’
Here’s the science: Women carry two X chromosomes, while men have one X and one Y. To prevent double expression of genes, one of women’s X chromosomes is largely silenced through a process called X-inactivation. The UCSF team discovered that this silencing becomes imperfect with age, causing previously dormant genes to activate.
Key findings from the UCSF team’s research include:
- LATE-LIFE ACTIVATION OF HIDDEN POTENTIAL: The second X chromosome ‘awakening’ activates genes that enhance brain health and learning capacity.
- BRAIN RESILIENCE & REJUVENATION: Genes supporting brain connectivity, memory, and cognitive resilience are kicked into action, confirming midlife as a period of growth, not decline.
- NATURAL ADVANTAGE FOR MIDLIFE LEADERSHIP: Women’s brains appear biologically designed to maintain adaptability, learning capacity, and cognitive strength longer.
“In typical ageing, women have a brain that looks younger, with fewer cognitive deficits compared to men.” says Dena Dubal, Professor of Neurology at UCSF and the senior author of the paper (published in Science Advances in March 2025).
Implications for Leadership and Organisational Systems
This research establishes a biological, not just sociocultural, basis for longevity and vitality in women as we age. Men lack this second X chromosome boost, yet stereotypes and organisational systems have historically privileged male leadership longevity.
Organisations ignoring or actively pushing women aside at midlife aren’t just being unjust, they’re discarding their most cognitively capable leaders precisely when their biological advantages are beginning to flourish.
QUESTIONS TO REFLECT ON:
- What if our biases about aging female leaders are not just socially unjust but scientifically WRONG?
- How might talent development change if we recognised this biological advantage?
It seems there may be a profoundly positive payback for the slightly squirrely time we experience during the perimenopausal neural rewire.
The silent X is silent no more, and neither should be the women who carry it!
PS: If you’re interested in reading the source research, you can access it HERE on the UCSF site.
