Mystery stories love a familiar sequence: the first person to discover something horrible screams, people elsewhere hear it, everybody rushes to the scene, and the plot begins.
If you have watched enough Detective Conan, the rhythm is almost automatic.
First discoverer: “Aaaah!”
Everyone else: “What happened?”
Viewer: “Well, there is the case.”
As a storytelling device it can look comically repetitive. As human communication, however, it makes surprising sense.
A scream is not merely a useless noise produced by panic. Human screams often contain acoustic properties that differ sharply from ordinary speech, grab attention, and tell nearby listeners that something outside the normal range of events may be happening.[1][2]
That makes the claim “screaming never helps” too simple.
But the opposite claim — “people who can scream are biologically superior, and quiet people die” — is also far too simple.
Severe threat can produce several defensive responses, including freezing and tonic immobility, in which movement and even vocalization can become difficult or impossible.[3]
A scream can function like a human emergency alarm.
That does not mean a person whose alarm fails to sound is defective.
1. The first discoverer in a detective show is actually transmitting information
Break the classic “first discoverer screams” scene into an information problem and it is remarkably efficient.
The witness may not yet understand what happened.
They may only know that someone is down, there is blood, a stranger has entered, or something exploded.
They do not need to compose a complete verbal report.
The sound alone can broadcast:
“Something here is far outside normal conversation.”
One vocalization can reach several people at once.
In mystery fiction, the scream looks like a “body discovered” flag because the protagonists immediately run toward it.
But in communication terms, one person who knows about the anomaly has just pushed an alert to a group that did not.
The first discoverer is not merely screaming.
They are the scene’s push-notification service.
2. Screams contain acoustic features that are hard to ignore
A 2015 Current Biology study found that human screams make strong use of an acoustic region associated with “roughness,” involving rapid amplitude modulations roughly around 30–150 Hz that are less typical of ordinary speech.[1]
Rough sounds stand out.
In the experiments, greater roughness increased detectability, and roughness was associated with activity in neural systems involved in rapidly evaluating danger.[1]
Artificial alarms use related acoustic strategies.
That is a fascinating convergence: a human throat and an engineered alarm are very different devices, yet both benefit from producing a sound the listener cannot easily file away as background.
An ERP study also found early differences in brain responses to fearful nonverbal vocalizations beginning around 150 milliseconds after sound onset.[2]
The listener does not need to finish a conscious internal sentence such as:
“Someone appears frightened, therefore I should investigate.”
The sound interrupts first.
That is the point.
3. If a whole group screams, “the dangerous thing is probably over there” becomes a reasonable inference
One person screaming can mean many things.
An insect.
A roller coaster.
A celebrity appearing unexpectedly.
Humans also produce screams of joy, pleasure, pain, anger, and fear; screams are not a single-purpose threat code.[4]
So one scream does not prove a crime or disaster.
But if many people in the same area scream and begin moving away from the same direction, the observer receives more information.
There is no simple study showing that “ten screams increase danger-detection accuracy by X percent,” so this should not be presented as a measured law.
It is an inference: the explanation “one person has an unusual reaction” becomes less sufficient when many people show converging alarm behavior.
Naturalistic research during white-water rafting found that fear vocalizations within a group were associated with fear vocalizations in other members, suggesting that fear expression can propagate socially.[5]
Research on crowd perception likewise shows that people process collective bodily expressions of fear.[6]
So the everyday logic is not absurd:
One person: “Aaaah!”
Bystander: “What?”
Ten people screaming and running toward you:
Bystander: “Whatever it is, I should probably pay attention to that direction.”
The crowd’s response becomes information about the environment.
4. “Screams switch off normalcy bias” is a good metaphor, not an established mechanism
Online explanations sometimes say that a scream “breaks normalcy bias.”
The intuition is easy to understand.
A street looks normal.
Then a piercing scream cuts through the scene and several people start running.
Someone who had been thinking “maybe it is nothing” may suddenly reassess the situation.
But the evidence should be described carefully.
The research supports claims such as:
- screams and fear vocalizations capture attention;
- emotional nonverbal sounds can be processed very rapidly;
- alarm calls can carry information about threat and avoidance;
- observers process fear expressed by crowds.[1][2][6][7]
That is not the same as proving a one-to-one psychological switch called “normalcy bias off.”
So the phrase works best as an explanatory metaphor, not as a literal neuroscience finding.
5. A scream can recruit other people into the situation
This is also why public-safety guidance sometimes recommends raising one’s voice or using an alarm to seek help.
Japan’s National Police Agency advises victims in relevant situations to call for help by raising their voice or using safety tools, and emphasizes that people nearby need to notice personal alarms.[8]
The value of sound is therefore not limited to startling an aggressor.
It can recruit third parties.
At first, only Person A knows there is a problem.
A shouts.
B and C turn around.
D realizes something abnormal is happening.
Someone moves away, calls for help, or contacts authorities.
The information network expands.
Of course, making noise is not always the safest choice. Some emergencies require concealment or silence.
The correct conclusion is not “always scream.”
It is: “screaming can have a practical communication function.”
6. Some people genuinely cannot scream — freezing is not a moral failure
This is the most important correction.
From a calm chair, it is easy to say, “If you were in danger, just shout.”
Under severe threat, people do not always get voluntary control over their response.
Models of defensive responding distinguish orienting/freezing, flight, fight, tonic immobility, and other states depending on the threat and whether escape or resistance feels possible.[3]
Tonic immobility can include:
- inability to move despite not being physically restrained;
- inability to call out or scream;
- muscular rigidity;
- reduced responsiveness.[3]
So a person who responds to sudden violence with “uh… what…?” and cannot produce a loud voice is not automatically less intelligent, less brave, or less evolved.
They may not have chosen silence.
Their defensive system may have entered a different mode.
One person’s alarm comes out as sound.
Another person’s system locks down.
That difference is not a personality ranking.
7. “People who scream are biologically superior” contains one useful idea buried inside an exaggeration
The useful part is this:
During danger, a loud vocal signal can attract attention, recruit help, and spread information about an abnormal event.[1][8]
That is consistent with both laboratory research and practical safety guidance.
The exaggerated part is:
“people who scream are biologically superior,”
“people who do not scream die,”
or
“screaming generally raises survival probability.”
The studies cited here do not establish a universal mortality ranking between people who scream and people who do not.
Threats differ.
Distance differs.
Crowd size differs.
Escape routes differ.
And defensive reactions differ between people and situations.
A more defensible statement is:
When vocalizing is safe and a person can also take appropriate protective action, alerting others may be useful. But some people cannot vocalize under threat, and in some situations silence may be safer.
Less dramatic.
Much more accurate.
8. So Detective Conan’s “first-discoverer scream” is basically a human emergency broadcast
Look at the classic mystery scene again.
A body is discovered.
The witness cannot process it.
A scream.
Characters down the hall react.
Everybody converges.
Authorities are called.
The story starts.
We have seen the pattern so often that it feels like a joke.
Yet the communication logic is solid.
The first discoverer cannot instantly write a forensic report.
A scream takes almost no preparation.
It is acoustically unusual enough to seize attention.
If multiple people begin screaming and fleeing, the group response adds further environmental information.
So the final answer is not that screams are useless noise.
They are an old, blunt, extremely powerful human emergency broadcast.
But the system does not activate identically in everyone.
And there is no scientific basis here for calling someone “biologically incompetent” because they froze.
The first discoverer in Detective Conan was not merely panicking.
They were also sending one of humanity’s oldest push notifications.
References
References (8)
- Arnal, L. H. et al. (2015). Human screams occupy a privileged niche in the communication soundscape. Current Biology, 25(15), 2051–2056 pubmed.ncbi.nlm.nih.gov
- Rapid detection of emotion from human vocalizations. Journal of Cognitive Neuroscience pubmed.ncbi.nlm.nih.gov
- Kozlowska, K. et al. (2015). Fear and the Defense Cascade: Clinical Implications and Management. Harvard Review of Psychiatry. ; Translational Challenges With Tonic Immobility. https://pmc.ncbi.nlm.nih.gov/articles/PMC3237674/ pmc.ncbi.nlm.nih.gov
- Frühholz, S. et al. (2021). Neurocognitive processing efficiency for discriminating human non-alarm rather than alarm scream calls. PLOS Biology doi.org
- Emotion in the wilds of nature: The coherence and contagion of fear during threatening group-based outdoors experiences pubmed.ncbi.nlm.nih.gov
- From personal fear to mass panic: The neurological basis of crowd perception. Human Brain Mapping pmc.ncbi.nlm.nih.gov
- Beinnes, G. K. et al. (2025). Differential neural decoding of alarm and avoidance information from vocal alarm calls in humans. Communications Biology nature.com
- National Police Agency of Japan: victim assistance / personal alarm guidance. ; https://www.npa.go.jp/safetylife/seianki67/index.html npa.go.jp
