Fast hearts don't make better mothers, even in bats
Mother bats' hearts accelerate when they hear their pups crying — evolution has tuned them to respond to distress signals the way your own nervous system responds to a baby's wail, a sympathetic spike that pulls you toward action before thought arrives.
The researchers who found this were confirming what we already suspected about mammalian attachment, adding bats to the growing list of species where maternal intensity and physiological arousal track together. But the study stopped at describing the mechanism — it did not ask whether mothers with the fastest-accelerating hearts actually keep their pups alive at higher rates.
This gap matters because measuring a mother's cardiac response to her infant's distress assumes the response correlates with outcomes. In human parenting science, we measure heart rates, cortisol levels, neural activation in response to baby cries as evidence of bonding and maternal sensitivity, implying that more arousal equals better mothering.
But arousal and competence are not synonyms. A racing heart might indicate panic as easily as presence, or anxiety that undermines decision-making, or noise. Imagine bat mothers with moderate cardiac responses had pups that survived at equal or higher rates than mothers whose hearts quickened sharply. That would mean the physiological signature we read as "maternal intensity" is actually orthogonal to the thing it supposedly measures.
A racing heart might indicate panic as easily as presence.
”It would mean we have been using our own bodies as evidence without checking whether the body's story matched reality. This matters because you have probably encountered it in your own field, whatever that is. Seen someone's visible stress interpreted as dedication, watched intensity become a substitute for effectiveness, then watched both get rewarded regardless of actual results. The bat mothers are showing us something about how easy it is to mistake a nervous system's response for a competence signature. The heartbeat accelerates, we read it as care, and we stop looking.
In your own work, identify one metric you use as a proxy for competence—response time, visible effort, engagement level—and ask whether it actually predicts the outcome you care about.
