The stranger in the next seat

Some gatherings make a crowd feel one thing together: a stadium at a goal, a church at a hymn, a street before a march. It is natural to credit the place, as if a room could hold energy the way it holds sound. The measurements point somewhere less obvious. The shared state is real and can be recorded in people's hearts, but it is not in the place, and it is not shared by everyone in it. It runs between people who already belong to one another, around a moment they care about. The person in the next seat who belongs to no one there can be at a different event.

In San Pedro Manrique, a Spanish village of about 600 people, an annual ritual ends with people walking across a bed of glowing coals.¹ Ivana Konvalinka and colleagues recorded the heart rates of 12 of the 28 fire-walkers, of 9 spectators who were relatives or friends of a walker, and of 17 spectators who were visitors with no relation to anyone in the village.¹ The walkers' heart rates and their relatives' rose and fell together in fine detail across the ritual. The visitors' did not.¹

Both groups of spectators were seated throughout and neither walked.¹ They watched the same event. What differed was who they were to the people on the coals. The authors suggest the link "may be informational", since walkers and relatives were doing very different things with their bodies and were not touching.¹ Each relative was reading, very closely, one particular person, and watching the same thing turned out not to be the same as sharing it.

Not the building either

A later study from the same research group compared basketball fans at the University of Connecticut. Some watched home games in the arena, seated wherever their tickets put them in a crowd that averaged 8,344.² Others watched live on a 102-inch screen on campus, in groups of four strangers.² The heart rates of fans in the arena were more synchronised throughout, including at half-time, and the difference was not explained by how much they moved.²

Then the finding that matters most. How excited fans were, measured by heart rate alone, did not predict whether they described the game as transformative; how synchronised they were did, and only in the arena.² Feeling more did not change people. Feeling the same thing at the same time, among the crowd, did. The comparison is not clean: the screen groups were strangers watching away games, and the fans in both settings were largely committed to the team already.²

If the arena were the active ingredient, the peak should come inside it. A 2025 study of Brazilian football fans found otherwise.³ Before a state championship final in Minas Gerais, thousands of home supporters lined the avenue near the stadium for the Rua de Fogo, the street of fire, with flares, smoke, chants and the arrival of the team bus.³ The researchers fitted 17 fans with heart-rate monitors for four hours.³ On most of their measures, synchrony was higher during the street ritual than during the final itself, and 17 of the 34 surges they identified came during it.³ Adjusting for how much the fans were moving did not remove the effect.³ One monitor was worn by the driver of the team bus, who did none of the chanting or jumping, and as the bus reached the crowd the driver's heart rate fell into line with theirs.³

Where the energy is

On this evidence, the "energy" of a place travels along relationships. It needs people who are already tied to one another, by family or by loyalty to a team; it needs a moment they all care about, a walk across coals or a bus coming through smoke; and it needs them to be present to one another when it happens. A building can help by gathering such people and putting a moment in front of them. It is not the source.

That changes what the stranger in the next seat is doing. A tourist at San Pedro and a walker's wife sat through the same ritual, and their bodies recorded different events. Most people know the experience from the other side: arriving at someone else's celebration, a wedding in another family, a match between two teams one does not follow, and feeling the room's intensity without being inside it. On this evidence that is not shyness or a mood. It is an accurate reading of where the coupling runs.

It also suggests why some events feel empty in full venues while some of the most intense ones happen in car parks and streets. A crowd assembled by a ticket rather than by a tie may be dense and loud and still not do this.

The samples are small: 38 people in the village, 182 across 26 basketball games, 17 at one football final.¹²³ All three studies come from one research programme, and all use heart-rate synchrony as their stand-in for shared feeling. The authors name concerts, religious rituals and political demonstrations among the gatherings their findings bear on and that deserve study; none was measured.² Nothing here compares rooms by their design, so whether acoustics or sightlines add anything is open.