Adult love runs on the same wiring as infant attachment

Levine and Heller's foundational claim is that romantic attachment in adults isn't a separate system from the bond between infants and caregivers — it's the same evolved mechanism, repurposed. Just as an infant needs a reliable caregiver to feel safe enough to explore the world, adults in a romantic relationship rely on a partner as a kind of secure base, and the nervous system treats threats to that bond with genuine alarm, not mere inconvenience.

This borrows directly from attachment theory, developed by psychologist John Bowlby and tested through Mary Ainsworth's research observing how infants responded to separation from and reunion with their caregivers, which identified consistent patterns of secure and insecure attachment early in life.

The authors argue these same patterns resurface in adult romantic bonds, meaning your seemingly personality-driven reactions to a partner pulling away or leaning in are actually your attachment system running old, biologically serious code.

Takeaway: your intense reactions to a partner's distance or closeness aren't overreactions — they're your attachment system doing exactly what it evolved to do.