While many parents around the world instinctively hum lullabies or sway to soothe a fussy infant, a new study suggests that such behaviors may not be universal—and are more dependent on culture than biology. 

Published recently in the journal Current Biology, the study examined the Northern Aché, an Indigenous community of about 800 people in Paraguay, and found that singing or dancing to comfort babies is absent in their child-rearing practices. 

Anthropologist Kim Hill of Arizona State University, who has worked with the Northern Aché since the 1970s, noted that he never observed lullabies or infant-directed dancing during his decades of fieldwork. While the group does sing, their songs are generally about hunting, personal experiences, or ancestral stories—and none are performed for babies. 

Researchers believe that these findings challenge the long-standing idea that such behaviors are biologically ingrained. Instead, they argue that lullabies and dance are cultural constructs, learned and passed down through generations rather than encoded in our DNA.  One possible reason for the absence of these traditions in the Northern Aché may lie in their turbulent history.

The study points to demographic upheavals, including epidemics, forced child removals, and resettlement on reservations, which may have contributed to the loss of cultural practices. For instance, although Northern Aché ancestors once made fire, today the community typically maintains existing flames rather than creating new ones. 

The findings further highlight differences even within the broader Aché population. The Southern Aché, for example, do practice dance, suggesting that such traditions were likely lost in the Northern group due to early community splits and historical trauma. 

“This research shows that humans don’t automatically sing lullabies or dance to soothe infants—these are behaviors learned and maintained through cultural transmission,” said co-author Manvir Singh of the University of California, Davis.  While Singh doesn’t rule out the possibility that humans may have some genetic predisposition for responding to music or rhythm, he emphasizes that culture plays a much larger role than previously thought.

“This doesn’t refute the idea that we may have evolved for such behaviors,” he said. “But it does mean that maintaining them relies heavily on cultural continuity.” 

The study opens new avenues for understanding how trauma, displacement, and cultural disruption can influence the loss of seemingly fundamental human behaviors, urging researchers and caregivers to view parenting practices through a more culturally sensitive lens.