Why do we cry?

Why do we cry?

Author: BBC World Service November 21, 2025 Duration: 30:00

Tears of joy, tears of sadness, tears of frustration or tears of pain - humans are thought to be the only animals that cry tears of emotion. CrowdScience listener Lizzy wants to know: why do we cry for emotional reasons? What is its evolutionary benefit? And why do some people cry more than others?

It turns out that humans cry three types of tear: basal, reflex and emotional. The first kind keeps our eyes nice and lubricated and the second flushes out irritants such as fumes from the pesky onion, but the reasons for emotional tears are a bit harder to pin down.

Using a specially designed tear collection kit, presenter Caroline Steel collects all three kinds of tears. With them safely stashed in tiny vials, she heads to the Netherlands, to Maurice Mikkers’ Imaginarium of Tears. Looking at her crystallised tears under a microscope will hopefully unveil a mystery or two.

Marie Bannier-Hélaouët, who grew tear glands for her PhD, explains how the nervous system processes our emotions into tears. But why should we cry for both happiness and sadness, and for so many other emotions in between? Ad Vingerhoets, Professor of Clinical Psychology at Tilburg University, suggests we cry for helplessness - our bodies do not know how to process such intensity of feeling.

But do these tears bring relief? Lauren Bylsma, Associate Professor of Psychiatry at the University of Pittsburgh, has been studying heart rates during crying episodes to find out. With her help, we also explore if women do in fact cry more than men, and why that might be.

Presenter: Caroline Steel

Producer: Eloise Stevens

Editor: Ben Motley

Photo: Fisheye woman having a cry - stock photo Credit: sdominick via Getty Images)


Curiosity drives discovery, and CrowdScience from the BBC World Service is built entirely on that principle. Each episode begins not with a scripted lesson, but with a question sent in by a listener from anywhere in the world. These aren't simple queries with easy answers; they are the wonderfully complex, often quirky puzzles about everyday phenomena and cosmic mysteries that make us all stop and wonder. What does silence sound like? Could we ever photosynthesize like plants? How does a crowd's mood physically spread? The team then embarks on a genuine investigative journey, tracking down the specialists at the very edge of our understanding-neuroscientists, ecologists, physicists, and engineers-to piece together credible, compelling answers. Listening to this podcast feels like having a direct line to the labs and field sites where knowledge is being created. The conversations are deep yet accessible, transforming abstract concepts into relatable stories. It’s a collective exploration where listener curiosity sets the agenda, making each episode a unique and democratic look at the machinery of our world and beyond. You become part of a global community pondering life, Earth, and the universe, one thoughtful question at a time.
Author: Language: English Episodes: 50

CrowdScience
Podcast Episodes
How many dead people are on the internet? [not-audio_url] [/not-audio_url]

Duration: 34:07
CrowdScience listener Devin in Canada has just had a baby. Worried that all the good email addresses might be taken by the time his child needs one, he has already set up an account. But it got him wondering: how many em…
Can my veggie sausages save the world? [not-audio_url] [/not-audio_url]

Duration: 26:28
CrowdScience listener Lisa, who is from South Africa but now lives in the UK, has been a vegetarian for many years. Sometimes though, she still finds herself craving meats – like spaghetti bolognese or a burger. To satis…
Why do I love rollercoasters? [not-audio_url] [/not-audio_url]

Duration: 29:09
Your heart pounds, your chest tightens, your stomach drops and your legs feel weak and shaky. Your palms are sweating and a tingling rush spreads through your arms and fingertips as your brain is overwhelmed with feeling…
How do electric fish make electricity? [not-audio_url] [/not-audio_url]

Duration: 26:29
Some fish can deliver electric shocks with four times the voltage of the electricity in your plug sockets at home . Crowdscience listener Mouhammed in Cameroon was stunned by this, so he charged us with finding out how t…
Why am I warm blooded? [not-audio_url] [/not-audio_url]

Duration: 26:28
CrowdScience listener Matt wants to know why he's warm blooded. He started thinking about this when he was watching some ants during the recent heatwave in Europe and wondered why their blood didn't boil. What are the pr…
Why can't I concentrate? [not-audio_url] [/not-audio_url]

Duration: 26:29
Why is it hard to concentrate, and why does it feel like such hard work? The CrowdScience inbox is full of questions like that, so for this show we’re concentrating on concentration and focusing on how we focus. We’ll be…
Why is TB still killing people? [not-audio_url] [/not-audio_url]

Duration: 26:29
Tuberculosis kills more than a million people every year. It’s the world’s leading cause of death from a single infectious agent. This is despite the fact that we've had a cure for TB since the 1940s and a vaccine that’s…
Will I get hit by a meteor? [not-audio_url] [/not-audio_url]

Duration: 37:00
Stare up at the night sky, and if you’re lucky, you might see a shooting star. Some people might make a wish, but CrowdScience listener Scott in California in the USA, thinks differently. He’s wondering how dangerous the…
Is anything truly random? [not-audio_url] [/not-audio_url]

Duration: 27:09
We’re delving into the CrowdScience archive to give you another chance to hear an award-winning show from 2025. CrowdScience listener Dorit has a problem. She wants the tiles in her new bathroom to be arranged randomly b…
Are there diseases in space? [not-audio_url] [/not-audio_url]

Duration: 26:28
Space missions are searching for evidence of extra-terrestrial life. CrowdScience listener George in Kenya wants to know what could be up there, and if there’s a risk it could harm humanity. With rovers currently analysi…