Some findings challenge what we think we know. This one surprised me more than most.

For years, I’ve taught and read about the universality of certain human behaviours, especially when it comes to music. Lullabies and dance are almost always presented as cultural constants, popping up in every known society. They’ve even served as the cornerstone of evolutionary theories that argue musicality must be hardwired into our species: dancing for group bonding, lullabies for mother-infant communication. But then comes a study like this, and you realise: maybe we’ve been too quick to use the word “universal.”

In a new paper in Current Biology, anthropologists Manvir Singh and Kim Hill present over ten years of fieldwork among the Northern Aché, a hunter-gatherer group in Paraguay. In all those years—122 months, thousands of hours of observation, hundreds of nights in forest camps—they never saw a single instance of dancing or infant-directed song. Not once.

Let that sink in. No dancing. No lullabies. Not in how we typically understand them, nor even in the nuanced forms ethnomusicologists sometimes tease out of ambiguous descriptions. Instead, music among the Northern Aché appears solitary, limited in form, and tightly bound to specific content: men sing about hunting or social disputes, women mostly about the dead. No group music-making, no synchronised movement, no songs to soothe babies.

Does this mean humans aren’t born with a universal urge to dance or sing to their children? Not necessarily. Singh and Hill are careful not to deny a biological predisposition outright. Instead, they argue that while the capacity may be universal, the expression depends heavily on cultural transmission. Just like fire-making—another skill the Northern Aché have lost and now replace with ember preservation—dance and lullabies might be things we don’t automatically invent, but rather inherit, tweak, and pass on. Those practices can vanish if cultural conditions are disrupted, such as population bottlenecks or forced resettlement.

It’s a stark reminder of how fragile culture can be, and how intertwined it is with demography. The authors even suggest that what we see among the Northern Aché may be a version of the “Tasmania effect”: the loss of complex behaviours following isolation and decline.

To be honest, I didn’t expect this. And I still think: surely someone, at some point, hummed a melody while rocking a baby? Surely someone tapped a rhythm around the campfire? But this study pushes back—gently but firmly—against that intuition. It asks us to rethink assumptions, not what humans can do, but what they actually do, and how easily it might disappear when culture frays.

So maybe not everyone dances. Or at least, maybe not anymore.

Abstract of the study:

Dance and infant-directed song are often considered universal behaviors, a view that has been supported by considerable cross-cultural research. The conclusion that humans in every documented society engage in these behaviors has, in turn, influenced evolutionary theories of music, which often treat human musicality as an adaptation, with benefits stemming from moving in synchrony and/or singing to infants. Drawing on 122 months of fieldwork conducted between 1977 and 2020, we here report no evidence of either dance or infant-directed song among the Northern Aché of Paraguay. Excluding church singing introduced by missionaries, Northern Aché adults sing alone and in a very limited number of styles. Several lines of evidence suggest that dance and infant-directed song were lost following reductions in population size that curtailed cultural complexity among the ancestors of the Northern Aché. Although our observations are consistent with a universal psychological capacity for dance and infant-directed song, they indicate a critical role of cultural transmission in supporting these behaviors while demonstrating the value of testing claims of cultural universality in remote and minimally acculturated populations.