Breaking the Myth of the Unfeeling Reptile
For centuries, reptiles have been framed as little more than living fossils, cold-blooded machines acting on reflex and instinct, incapable of emotions, expectations, or anything resembling subjective experience. This view has not only shaped how they are studied but has also excused their mass exploitation. They are traded as “starter pets,” skinned for fashion, displayed in zoos as living ornaments, and experimented on in laboratories.
But science is catching up with something animal advocates have long known: reptiles are not primitive automatons. They think, they choose, they anticipate, and, as new evidence shows, they experience moods. Recent research on tortoises and geckos, combined with broader insights from neuroscience, dismantles the myth of reptilian simplicity and demands a radical reassessment of how humans treat them.
Moods in Tortoises
A study published in Animal Cognition in 2025 investigated whether red-footed tortoises could exhibit what scientists call “free-floating mood states.” Unlike emotions, which are immediate responses to specific events, moods are longer-term affective states detached from any single trigger. Detecting moods in reptiles would extend our understanding of their sentience — and undermine centuries of human arrogance that positioned them outside the circle of feeling beings.
Researchers used a cognitive bias test, a method already validated in mammals and birds. Fifteen tortoises were trained to recognise a “positive location” where a food bowl always contained arugula and a “negative location” where the bowl was always empty. Once they reliably distinguished the two, researchers introduced ambiguous bowl positions between the positive and negative spots. The logic is simple: if a tortoise rushed optimistically toward an uncertain bowl, it suggested a hopeful expectation. If they hesitated or avoided it, it indicated pessimism.
The results were striking. The tortoises generally showed an optimistic bias, they treated ambiguous locations more like the positive ones, approaching them quickly. Importantly, individual tortoises differed: some were more optimistic, others more pessimistic. These differences weren’t random quirks of personality; they correlated with behaviour in anxiety tests. Optimistic individuals extended their heads further, explored novelty more confidently, and approached unfamiliar objects faster. Pessimistic individuals behaved more anxiously.
For the first time, reptiles were shown not only to feel discrete emotions like fear or pleasure, but also to hold persistent moods that shape their behaviour over time. This dismantles the old view of reptiles as little more than twitching bundles of reflexes.
The Predictive Brain: More Than Instinct
If moods shape behaviour in tortoises, how do we explain the underlying mechanism? Here, the Bayesian brain hypothesis offers a powerful lens. Often called the “predictive brain” model, it suggests that animals (including humans) do not simply respond to raw sensory inputs. Instead, the brain constantly generates expectations based on past experiences, using them to interpret the present and anticipate the future.
This matters because it means an animal’s emotional response isn’t just about what’s happening now, it’s filtered through their history of experiences. A negative environment doesn’t just cause immediate stress; it warps expectations, creating pessimism and hopelessness. This is the foundation of what psychologists call learned helplessness: when repeated trauma teaches an individual to stop expecting relief, even if an escape becomes possible.
Studies on rats illustrate this clearly. Rats conditioned to expect pain relief from an injection later behaved as if relief had occurred, even when given a placebo. Their brains predicted an outcome and influenced their subjective experience accordingly. If rats, like humans, can develop placebo responses, then reptiles, with their demonstrated moods, may also form expectations that shape their feelings.
Consider what this means for animals in captivity. A reptile held in a barren vivarium, denied enrichment and choice, may come to expect monotony, deprivation, or even harm. Their affective state becomes not just reactive but predictive: pessimism embeds itself as the background to every interaction. This is not simply “stress.” It is a fundamental reshaping of the animal’s relationship with the world.
Geckos Want More Than Survival
If tortoises show moods, do other reptiles reveal preferences and desires that go beyond mere survival? A recent study on leopard geckos provides the answer.
Six geckos were rotated through three types of enclosures:
1. Standard: a bare setup with only the basics: a single hide, a small water bowl, and newspaper substrate.
2. Enriched Non-Naturalistic: added hides, climbing opportunities, fake plants, a larger water bowl.
3. Enriched Naturalistic: everything in the non-naturalistic setup, but with live plants and invertebrates to create a mini-ecosystem.
The geckos explored and used all enrichment items provided, clearly showing that these weren’t optional luxuries but behavioural needs. When given a free choice, the animals overwhelmingly preferred the naturalistic environments. They climbed more, submerged in water, and displayed a broader range of natural behaviours. By contrast, in standard enclosures they scratched at barriers, attempted to escape, and squeezed into tiny water bowls — frustrated expressions of thwarted needs.
This evidence shows that reptiles prefer enriched conditions. They make choices, they seek stimulation, and they gravitate toward complexity. To deny them this is not neutrality, it is a deliberate act of deprivation.
Shattering the Myth of Reptilian Simplicity
Together, these findings tell a consistent story: reptiles have inner lives shaped by moods, expectations, and preferences. The myth that reptiles are incapable of such experiences has served human supremacy well. It justifies their exclusion from welfare laws, their treatment as ornamental commodities, and their sale to children as disposable pets.
But the science is clear: reptiles are not unfeeling. They can be optimistic or pessimistic, hopeful or helpless. They can suffer when trapped in sterile environments and flourish when given complexity. To deny these truths is not scientific caution, it is moral cowardice.
From Science to Justice
So what do we do with this knowledge? If reptiles have moods and expectations, then:
🦎 The pet trade must end. No animal should be bred, shipped, and sold as a product. The evidence shows that reptiles demand more than glass boxes; they need autonomy and enrichment that captivity cannot provide.
🦎 Zoos must be abolished. Displaying reptiles in enclosures, no matter how decorated, treats them as living exhibits. Their preferences for naturalistic habitats cannot be met in display cases.
🦎 Experimentation must stop. Using reptiles in laboratories is not neutral “science.” It is a violation of beings with the capacity for hope, fear, and despair.
🦎 Fashion must reject reptile skins. Behind every handbag or belt is a life capable of experiencing more than instinct. Turning them into accessories is indefensible.
Justice requires more than minor reforms. It demands emancipation: recognising reptiles as subjects of their own lives, not objects for human use.
Reimagine Reptiles
The tortoise study, the gecko enrichment research, and the Bayesian brain framework together dismantle one of humanity’s most entrenched myths: that reptiles are too primitive to feel. The truth is that they not only feel but also expect, anticipate, and carry moods. They are predictive beings navigating their world with hope or despair, confidence or anxiety.
When a gecko scratches at the glass of a barren tank, they are not just “exploring.” They are expressing a thwarted desire for freedom. When a tortoise approaches an ambiguous bowl with optimism, they are not just reacting mechanically, they are revealing a mood state that shapes their relationship with the world. These are not trivial findings. They are cracks in the wall of denial that humans have built to justify exploitation.
Reptiles deserve more than survival. They deserve freedom from the cages, tanks, and chains that reduce them to commodities. They deserve recognition as sentient beings whose inner lives matter.
The evidence is in. Reptiles have moods. The question is whether humans will have the courage to change.