The XX Rules: Non-Negotiable Rules of Being Female
1. We Bear the Greater Costs of Sex and Reproduction
Females invest more biologically in reproduction, from egg production to pregnancy, birth, and lactation. This influences the design of our brain and body, even if we have no plans to have children. It shapes everything from our sexual psychology to the ways we compete.
2. Our Hormones Cycle
Our sex hormones don’t stay static—they ebb and flow across the menstrual cycle, life stages (puberty, pregnancy, postpartum, perimenopause), and in response to environmental cues. These fluctuations impact our metabolism, immune system, brain, behavior, and emotions.
3. We Are Most Powerful When in a State of Balance
The female body thrives on cycles of exertion and recovery. Whether it’s the menstrual cycle, exercise, cognition, or childbirth, we are wired to push and then restore. Chronic overdrive without repair leads to burnout and dysregulation.
4. Our Brains Are More Interconnected
Compared to males, female brains show more crosstalk between hemispheres and between emotion-processing and executive areas. This contributes to greater emotional awareness, verbal fluency, and intuitive social reasoning.
5. We’re an Immunological Powerhouse…but More Inflammatory
Estrogen ramps up immunological vigilance, giving us an edge in fighting infections. But this same immune sensitivity also makes us more prone to autoimmune and inflammatory conditions.
6. Our Physiology Prioritizes Safety and Energy Efficiency Above All Else
Evolution has wired the female body to conserve resources and protect reproductive capacity. Under stress, scarcity, or social threat, it downshifts fertility, libido, and energy output. It also makes it easier for us to gain weight, harder to lose it, and makes us more likely to experience anxiety when we’re not in relationships.
7. We Are Built to Evolve
Female brains undergo large-scale remodeling during puberty, pregnancy, postpartum, and menopause. These changes shift our priorities, cognition, and how we think, feel, and experience the world. Our brains adapt dramatically across life phases to meet new demands.
8. We’re Sensitive to the Social
Our neurobiology makes us especially attuned to relationships, belonging, and emotional safety. This isn’t fragility; it’s adaptation. Our HPA axis (stress axis) is more sensitive than men’s. The female brain evolved in tight social ecosystems where connection was survival and failure to form groups would have led to their demise.
9. We’ve Been Seen Before We’ve Been Heard
Because female fertility is transient and invisible, human cultures have long used appearance – youth, skin quality, body shape – as a proxy for a woman’s ability reproduce. This means that – as much as we might hate this to be true – women have evolved to monitor their appearance more vigilantly than men, and we’ve been taught to see our bodies through the eyes of others.
10. We Perceive More
Research finds that women have greater sensitivity to touch, smell, and pain. This reflects different thresholds for detecting threat or opportunity – useful in parenting, mate choice, and social contexts. Our sensory systems are finely tuned – and can become sometimes overloaded.
11. Our Design Is Not a Disorder
Being female isn’t a deviation from a male norm, it’s its own blueprint. When medicine ignores or pathologizes how we are built, it creates dysfunction and we think our body is the enemy. When we work with our biology instead of against it, we thrive.
The XX Rules is not another wellness system.
It’s a total reframe of how women understand, support, and lead with their biology. It validates what you’ve always felt, and finally gives you the science to back it up.