Recently, scholars studied vagus nerve behavior during choral singing. "Choir singing is known to promote well-being," the study conducted by a Swedish research team from the University of Gothenburg led by Bjorn Vickhoff begins. This study sought to flesh out what many ministers have come to take for granted, or, in other cases, perhaps could use some reminding especially after incidents of trauma. You can view a film of the researchers discussing the implications of their study here.
The study explores why singing appears to be a universal phenomenon. "Unlike most other universal human behaviors there is no self-evident Darwinian explanation." Instead, the universal nature of singing may be due to its group bonding results and its inherent collective calming abilities. Singing achieves relaxed and corporate communicative states, partly because "external and visible joint action corresponds to an internal and biological joint action."
The study acknowledges that the vagal effect of breathing is a calming reaction. They explain "how the length of the song phrases guides respiration, resulting in compliances of frequency and phrases of respiration cycles and [heart rate variability] HRV cycles between singers." In other words, when a congregation sings together, their heart rates and breathing come in sync, and, collectively, they relax. The study concludes, singing "produces slow, regular and deep respiration . . . [that] causes a pulsating vagal activity," which is collectively calming.
This is good news for ministers seeking to lead congregations after trauma. Gathering, for worship, after incidents of trauma – especially when worship involves singing – can produce all three of the keys to healing from trauma.