The Rest Is Science — Episode Summary

Podcast: The Rest Is Science
Episode: Do animals know they’re lying?
Hosts: Professor Hannah Fry & Michael Stevens (Vsauce)
Date: February 17, 2026

Episode Overview

This episode dives into a deceptively simple but profound question: Can animals lie? Professor Hannah Fry and Michael Stevens dissect the different layers of deception in the animal kingdom, from involuntary camouflage to strategic, learned trickery, and ultimately to the question of whether any non-human animal truly possesses the complex, intentional manipulation of belief we call "lying." Engaging stories, witty banter, and accessible science abound as the hosts probe animal cognition, evolutionary deception, and the elusive concept of “theory of mind.”

Key Discussion Points & Insights

1. Setting the Stage: From Personal Lies to Animal Deception

• The episode opens with Michael confessing to a small, harmless personal deception involving a gift exchange with Hannah, setting a humorous, self-aware tone for the discussion.

  “I can always get another set of Swords of Truth.” — Michael Stevens (02:04)

• This soul-searching segues into the central question: What is lying, and can animals do it, or is it uniquely human?

2. Taxonomy of Deception: From Camouflage to Intentional Trickery

(04:06-07:26)

• Involuntary Deception:

  • Stick insects look like sticks; butterflies have false eyespots; mammals and reptiles may mimic the colors or appearance of venomous counterparts.
  • But this is built-in — not a behavioral choice.

  “Is it pretending to be a stick? That seems to give it a lot of agency.” — Michael (04:42) "It’s more like a meta-level evolutionary deception.” — Hannah (05:42)

• Pre-programmed (Reactive) Deception:

  • Chameleons and cuttlefish can change their appearance in response to threats.

  “It’s not like saying today I’m going to be pink... it’s reacting to its environment.” — Hannah (07:00)

  • Here, there is some behavioral reaction, but it’s largely instinctive, not calculated.

3. Deceptive Behaviors with Agency: The Case of the Cuttlefish "Sneaker Males"

(07:26-10:24)

• Male Australian giant cuttlefish face a mating competition (four males per female). Smaller “sneaker” males disguise themselves as females to infiltrate harems, bypassing larger rivals and sometimes successfully mating.
  • The deception is strategic and reactively behavioral — allowing some flexibility and “choice.”

  “They mimic being like a cute girl... while the big male either isn’t looking or mistakes it for a female.” — Guest (09:27) "It feels like there’s some autonomy involved in this." — Hannah (10:38)

4. Sophisticated, Possibly Learned Deception: The Penguin "Pebble Ruse"

(11:22-15:43)

• In historical observations, female Adélie penguins were documented offering “fake courtship” to trick males into gifting them valuable pebbles, then bolting back to their actual mates without reciprocating.
  • Is this a learned behavior or spontaneous? Evidence is ambiguous.

  “She’ll wait for him to present a stone, and then… grab the stone and run off…” — Guest (14:31) “This goes on one level from the cuttlefish, because this is no longer just a mimicry of the physical shape. This is getting another member of your own species to make a false prediction about your future behavior.” — Hannah (15:38)

5. Intentional, Learned Deception: Rhesus Macaque “False Alarm”

(18:26-19:34)

• Low-ranking macaques sometimes give predator cries when no hawk is present, causing others to flee, leaving food unguarded — deliberately manipulating others’ behavior for gain.

  “That is the sort of functional deception that you’re describing…” — Guest (18:48)

6. Philosophical (and Psychological) Threshold: Theory of Mind

(31:26-52:42)

• True lying, the hosts argue, requires theory of mind: knowing others have beliefs distinct from your own, and those beliefs can be false.
• The Sally-Anne Test (32:20-34:06):
  • Young children under ~4 years fail this test; they can’t yet infer false beliefs in others.
  • Michael and Hannah reflect on personal parenting experiences as analogous to animal cognition.

  “I told her that every time she lied, a light would shine out of her eyes.” — Guest (34:29) "No animal has ever asked us a question... They have never shown themselves to see others as sources of information in novel ways.” — Michael (51:35)

7. Animal Studies: Do Apes Have Theory of Mind?

(36:13-46:30)

• Chimpanzee "Haystack/King Kong" Experiment (2016) (39:07-41:03):
  • Chimps watched a costumed human (“King Kong”) hide in haystacks. Using eye-tracking, researchers found chimps anticipated where a human with a false belief would look for King Kong, not just where King Kong really was.

  “The chimpanzees look where the human would think King Kong is.” — Michael (40:24)

• Begging/Bucket Experiments (43:03-43:59):
  • When forced to beg for hidden food, chimps didn’t distinguish between humans who knew where the food was and humans who didn’t — failing to show a nuanced understanding of ignorance/knowledge.
• Dominance/Windows Food Hiding Study (44:21-45:33):
  • Subordinate chimps would avoid food they saw the dominant watched being hidden, but would go for it if the dominant didn’t see — hinting at some social knowledge, but rule-based or truly mind-based?

  “There’s a lot of pressure to ... make sure that we 100% know this is a theory of mind and not just a rule-based behavior. And we still don’t know.” — Michael (46:30)

8. Coco the Gorilla and the Limits of Animal Lying

• Famous gorilla who could use sign language; once broke a sink and blamed it on her kitten, signing "cat did it." But is this genuine lying or mimicry of past associations/reward structures?

  “The cat did it.” — Coco, via sign language (47:32) “Superficially that looks to me like a human kind of lie… but you can’t be sure.” — Hannah (47:51)

• Notably, animals like Coco have never been documented asking questions, which Michael suggests is a key criterion for true theory of mind and “top-level” lying.

  “Once a species can ask questions, that’s when it can tell lies.” — Michael (51:35)

9. Human Lying, Animal Lying: Where to Draw the Line?

• Humans lie with intent to manipulate belief and are held morally responsible. Animal “lies” seem less blameworthy — automatic or learned strategies rather than deliberate betrayal.
• Michael pushes for a generous approach: assume animals may have theory of mind, but recognize the difficulty of truly knowing.

  “Of course [animals] can [lie]. Humans lie — we are animals!” — Michael (48:56)

Notable Quotes & Moments

• On animal agency and deception:

  “It can’t help the fact that it is stick-shaped. That is involuntary deception.” — Michael (04:42)

• On penguin pebble trickery:

  “She’ll run off back to her mate who’s guarding the nest.” — Guest (14:31)
  “This is getting another member of your own species to make a false prediction about your future behavior.” — Hannah (15:38)

• On macaque strategic cries:

  “There’ll be a cry that goes out for a hawk nearby and there’s no, no hawk anywhere... One clever little monkey ... will run in and like steal a little bit of food before the others come back.” — Guest (18:41)

• On theory of mind definition:

  “The ability to understand that other organisms aren't just responding to reality, they are responding to their beliefs about reality.” — Michael (31:26)

• On children and lying:

  “No animal has ever asked us a question. ... They have never shown themselves to see others as sources of information in, in novel ways.” — Michael (51:35)

• On moral judgment:

  “When I see a stick bug, I don't put my nose up in the air and go, the liar... But when a person lies ... this is morally disgusting.” — Michael (27:00)

Key Timestamps for Segments

• Confession and framing the topic: 01:04–02:29
• Nature of deception vs. lying: 04:06–07:26
• Cuttlefish sneaker males: 07:33–10:24
• Adélie penguin “fake courtship”: 11:22–15:43
• Rhesus macaque false alarm: 18:26–19:34
• Defining theory of mind, Sally-Anne test: 31:26–34:06
• Chimpanzee haystack experiment: 39:07–41:03
• Dominant/submissive chimp food hiding: 44:21–45:33
• Coco the gorilla “cat did it” sign: 47:32–48:22
• Theory of mind, question-asking, and final thoughts: 50:04–53:46

Final Thoughts & Takeaways

The episode ultimately suggests that deception is widespread throughout the animal world, but true lying — the manipulation of others’ beliefs with intent and with a nuanced understanding of minds due to theory of mind — may be uniquely or at least distinctly human.

• Most animal “lies” fall within involuntary (camouflage), instinctive (deceptive displays), or learned/trial-and-error (alarm cries, mimicry) forms of deception.
• Complex “manipulation of belief” seems to require theory of mind, which is hotly debated in animal cognition. Recent research in great apes is tantalizing but not definitive.
• Animals like Coco exhibit fascinating behavior, but their actions may be sophisticated begging or reward-seeking, not genuine manipulations of belief.
• Until an animal asks us a question or clearly demonstrates understanding of another’s ignorance, the distinction between human and animal lying may be best seen as a spectrum rather than a strict divide.

Closing Banter:
The hosts wrap up by debating how much lying should actually be tolerated — and whether, in the end, all of us are a little bit deceptive, animal or not.

Useful and entertaining for the endlessly curious, this episode leaves listeners uncertain of the boundaries between truth, lies, and animal minds — and hungry for more scientific sleuthing.