The Science of Crowds

What happens to our brains and bodies when we gather with thousands of strangers at music festivals, concerts, or gigs? This week, as All Together Now kicks off in Curraghmore, County Waterford, Professor Luke O’Neill dives into the fascinating science of crowd behaviour – and why being part of a crowd can feel so good, or sometimes so dangerous.

Humans are, at heart, social animals. We evolved to thrive in groups — for protection, for connection, and even for love. Whether you're losing yourself in a packed mosh pit, swaying with strangers to your favourite band, or experiencing a collective chant under the night sky, there’s a deep biological and psychological process at work. Luke explores how music festivals spark a surge in oxytocin, the so-called “magic hormone” that fuels feelings of bonding, euphoria and transcendence. He also explains how we unconsciously mirror one another in crowds, sometimes entering what he describes as a social “trance.”

But it’s not all good vibes. History is full of examples of how crowds can turn deadly when density goes too far, leadership breaks down, or panic spreads. Luke unpacks the science of crowd crushes, fluid dynamics, and behavioural prediction — including real-world examples from Pamplona’s Bull Run to school corridors, and from murmurations of starlings to stampeding buffalo.

We learn how the best defence against crowd risk might be shared passion — if everyone’s there for the same reason, the group behaves more cooperatively, instinctively regulating itself. That’s why the safest crowd at a festival might just be the one most in love with the music.

If you're heading to a festival or concert this weekend, enjoy the crowd — you’re not just part of the atmosphere, you are the science.

🎧 Newstalk will be live at All Together Now all weekend from the Go Loud Lounge on site, with a packed schedule of interviews, games, and live events. Keep an eye on Newstalk’s socials for the full festival lineup.

🔗 More info: newstalk.com/all-together-now
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📬 Have a question or topic suggestion for Luke? Email him directly at laoneill@tcd.ie