The Psychology of the Extinct: What Can We Know About Dinosaur Behaviour?
Psychology has a slight problem when it comes to dinosaurs.
The patients are dead.
Not recently dead. Not “we can still get a decent case history from the family” dead. Dead for tens of millions of years. Their soft tissues are gone. Their nervous systems are gone. Their habits, preferences, routines, irritations, mating rituals, and tiny private grudges have all been filtered through geological time until what remains is mostly bone, stone, footprint, tooth mark, egg, and vibes.
Scientific vibes, ideally.
This makes the psychology of dinosaurs a peculiar thing. You cannot give a Triceratops a questionnaire. You cannot put a Velociraptor in a maze. You cannot ask a Tyrannosaurus rex whether it ate the hadrosaur because it was hungry, bored, socially excluded, or simply working through something.
And yet we do know things.
Not everything. Not the clean, cinematic, emotionally satisfying things people often want to know. We do not know whether a young dinosaur missed its mother. We do not know whether a predator felt frustration when prey escaped. We do not know whether a crested dinosaur recognised another individual in anything like the way a crow, dog, elephant, or person might.
But behaviour leaves traces.
Not always obvious ones. Not always honest ones. But traces nonetheless.
A footprint is behaviour. A nest is behaviour. A healed injury is behaviour plus survival. A bite mark is behaviour with teeth. A trackway is movement made permanent by accident. A skull is not a mind, but it can tell us something about the sensory world that mind once lived inside.
So the question is not really, “Can we psychoanalyse dinosaurs?”
Thankfully, no.
The better question is: how much of a vanished inner life can be reconstructed from the marks it left outside itself?
The Problem With Studying Dead Minds
Most psychology begins with living behaviour. Someone presses a button, avoids a stimulus, remembers a word list, copies an action, follows a crowd, clings to a caregiver, misreads a facial expression, or explains their worst decision using language so flimsy it deserves its own hazard tape.
With dinosaurs, we do not get behaviour in real time. We get aftermath.
This is why dinosaur behaviour is usually studied through palaeontology, comparative anatomy, palaeoneurology, evolutionary biology, and trace fossil analysis rather than traditional comparative psychology. The method is indirect. Researchers infer behaviour from fossils, trackways, nests, injuries, braincase anatomy, sensory structures, and comparison with living relatives. That kind of work is necessarily cautious, because the fossil record preserves death much more reliably than it preserves personality. Studies of function and behaviour in the fossil record make exactly this point: behaviour can be inferred, but only through physical evidence and comparison, not through fantasy taxidermy with opinions.
That is annoying, but it is also fascinating.
Because psychology is already an inferential science. We infer minds from behaviour all the time. Even with living humans, we rarely see the thing itself. We see speech, action, avoidance, posture, memory, habit, error, and context. Then we build a model of what might be happening underneath.
With dinosaurs, the inferential gap is just larger.
A lot larger.
Roughly asteroid-sized.
Behaviour Leaves Footprints
Footprints are among the most psychologically interesting fossils, because they are not simply remains of a body. They are remains of an action.
A bone says, “Something died.”
A footprint says, “Something moved.”
That distinction matters. Trackways can suggest how an animal walked, how fast it travelled, whether it moved alone or alongside others, whether several animals were heading in the same direction, and whether different age groups or even species may have been travelling together.
This does not mean every set of parallel footprints is a prehistoric family outing. Mud is not a diary. A group of animals might leave similar tracks because they were migrating, escaping danger, following water, passing through a narrow landscape, or dying in the same unfortunate place at different times. Fossils are brilliant, but they are also rude. They rarely explain themselves.
Still, trackways are some of the closest things we have to dinosaur behaviour caught in the act.
Recent evidence has even suggested possible mixed-species herding from 76-million-year-old dinosaur footprints in Canada, interpreted as a rare glimpse into social movement among multiple dinosaur species. That does not mean dinosaurs had a multicultural friendship group with shared values and a WhatsApp chat. It does mean that movement, grouping, and possibly safety in numbers can sometimes be inferred from the fossilised geometry of feet.
Which is wonderfully strange.
The mind is gone. The mud remembered.
Nests, Eggs, and the Question of Care
Parenting is one of the few psychological acts that can leave a geological signature.
Not the love part. Not the worry. Not the sleep deprivation. Not the quiet resentment of having produced something loud, fragile, and expensive.
But the nest? The eggs? The hatchlings? The spacing of breeding sites? The presence of juveniles? Those can survive.
One of the classic examples is Maiasaura, whose name is often translated as “good mother lizard.” Fossil nesting sites associated with Maiasaura have been central to arguments about dinosaur parental care, especially because nests, eggs, hatchlings, and juveniles can suggest that at least some dinosaurs did more than simply lay eggs and wander off like emotionally unavailable handbags. The Natural History Museum describes Maiasaura as one of the most famous examples used in discussions of dinosaur nests and parental behaviour.
But again, caution matters.
A nest does not prove tenderness. A hatchling near an adult does not prove bedtime stories. Evidence for care is strongest when multiple clues converge: nest structure, developmental stage of young, tooth wear, clustering, adult proximity, and comparison with living birds and crocodilians.
This is where the psychology becomes subtle. We are not asking whether dinosaurs were “good parents” in a human moral sense. We are asking whether selection favoured behaviours such as guarding, brooding, feeding, protecting, or remaining near offspring.
That is not sentimental.
It is behavioural ecology with a tiny Jurassic lump in its throat.
The Social Dinosaur
For a long time, popular culture gave us two basic dinosaur personalities.
The herbivores were cows with architecture.
The carnivores were knives with legs.
This was never enough.
Some dinosaurs seem to have lived socially, at least some of the time. A major study of Mussaurus patagonicus found eggs and skeletons from many individuals at different life stages in Patagonia and interpreted the site as evidence of early herd-living, colonial nesting, and age segregation around 193 million years ago. The authors argued this represented the earliest evidence of complex social behaviour in dinosaurs, pushing such behaviour much deeper into dinosaur history than previously known.
That is a big deal.
Age segregation is especially interesting because it implies that the animals were not merely dying in a heap. They may have organised, moved, or gathered in ways partly structured by life stage. Young with young. Adults with adults. The prehistoric equivalent of a school trip, a staff meeting, and everyone silently agreeing not to mix the two.
But sociality is not one thing.
A herd can be a defence system. A mating arena. A feeding strategy. A migration pattern. A nursery. A traffic jam with hooves. Group living does not automatically mean friendship, empathy, cooperation, or a rich emotional life. It does, however, suggest that some dinosaurs had to navigate the presence of others.
And that matters psychologically.
Because the moment an animal lives around others, behaviour becomes social. It must coordinate, avoid, compete, signal, follow, threaten, court, tolerate, or escape. Even very simple social systems create pressures on perception, memory, timing, recognition, and decision-making.
A dinosaur did not need to be a philosopher to care who was standing next to it.
Especially if who was standing next to it had teeth.
The Braincase as a Haunted House
If nests and footprints give us behaviour from the outside, skulls sometimes let us peer at the architecture from within.
Palaeoneurology studies fossil brains indirectly, often through endocasts: natural or digital casts of the space inside the skull. Modern CT scanning allows researchers to reconstruct aspects of brain shape, cranial nerves, inner ear structures, and sensory regions. This does not give us thoughts. It gives us constraints. It tells us something about the equipment an animal had for perceiving and responding to the world.
A 2024 review described dinosaur palaeoneurology as an evolving field linked to broader evolutionary neuroscience, especially as CT scanning and digital reconstruction improve what researchers can infer from fossil skulls.
This is the scientific version of walking through an abandoned house and trying to infer the life that once happened there.
Large olfactory regions may suggest smell mattered. Inner ear anatomy may tell us something about balance, posture, or hearing. Eye and skull anatomy can suggest visual priorities. Brain proportions can raise questions about sensory processing, motor control, and behavioural flexibility.
But this is also where people get overexcited.
The temptation is obvious: bigger brain, smarter dinosaur. Lovely. Easy. Wrong enough to be dangerous.
Brain size matters, but it is not intelligence in a jar. Neuron density, body size, ecology, development, sensory specialisation, and evolutionary history all complicate the picture. A brain is not a leaderboard.
This became especially clear in the recent debate over T. rex intelligence. One line of argument suggested large theropods may have had surprisingly high neuron counts and cognition comparable to some primates. A 2024 reassessment argued that such claims were probably overstated and that extinct animal cognition cannot be confidently reconstructed from neuron estimates alone. The newer critique called for a broader approach using palaeontology, living animal comparison, anatomy, and behavioural evidence rather than turning T. rex into a scaly baboon because the numbers briefly looked fun.
This is the sensible position.
T. rex was probably behaviourally sophisticated in ways suited to being T. rex.
Which is different from being a monkey.
And, frankly, probably more useful when your head is a demolition tool.
Birds: The Dinosaurs Who Stayed
The easiest way to study dinosaur psychology is to look out of the window.
Birds are living dinosaurs. More precisely, they are the surviving avian branch of theropod dinosaurs. Most dinosaur lineages went extinct after the end-Cretaceous mass extinction, but birds survived and diversified into thousands of species. The Natural History Museum describes birds as the only dinosaurs that remained after the extinction event, and the RSPB similarly describes birds as the only known living dinosaurs descended from theropods.
This matters because bird cognition is not a side note to dinosaur behaviour.
It is part of the dinosaur story.
Modern birds show extraordinary behavioural complexity. Corvids solve problems, cache food, recognise individuals, and use tools. Parrots learn vocal patterns and manipulate social attention. Pigeons categorise visual stimuli with the grim competence of tiny feathered statisticians. Chickens have social hierarchies, communication systems, and learning capacities that people routinely underestimate because they are too busy turning them into nuggets.
This does not mean extinct theropods were secretly ravens in Halloween costumes.
Evolution does not work by copy and paste. Modern birds have had 66 million years of their own evolution since the non-avian dinosaurs disappeared. A crow is not a tiny Velociraptor with better PR.
But birds show us that dinosaur brains, at least on the avian branch, were capable of far more than the old “giant stupid reptile” stereotype allowed. The dinosaur-bird connection also means some behaviours we think of as bird-like may have deeper dinosaurian roots, including feathers, brooding-related behaviours, display structures, and complex sensory-motor coordination. The Natural History Museum notes that many features and behaviours associated with living birds were also present in their dinosaur ancestors.
So perhaps the better comparison is not “were dinosaurs like reptiles or mammals?”
It is: which dinosaurs, in which ways, under which ecological pressures?
That answer will vary dramatically.
A sauropod, a troodontid, a hadrosaur, an ankylosaur, and a crow are all part of the broader dinosaur story, but treating them as psychologically interchangeable would be like studying humans, bats, cows, and dolphins and concluding: “Mammals are clingy.”
True in places. Useless as a theory.
What We Probably Know
So, what can we say without embarrassing ourselves?
We can say that some dinosaurs likely lived socially, at least in certain contexts. Herding, group movement, colonial nesting, and age-structured assemblages all suggest that dinosaur social life was real, though varied across species and environments. The Mussaurus evidence is especially important here because it suggests complex social behaviour appeared early in dinosaur evolution.
We can say that some dinosaurs likely engaged in parental or reproductive behaviours more complex than simple egg dumping. Nesting evidence, brooding postures in some theropods, and comparison with birds and crocodilians support the idea that reproductive behaviour varied widely and sometimes included care.
We can say that dinosaur sensory worlds differed. Some probably relied heavily on smell. Others on vision. Others on balance, hearing, display, or social signalling. The braincase does not tell us what they thought, but it can tell us what kind of world their nervous system was built to notice.
We can say that intelligence was not evenly distributed. There was no single “dinosaur mind.” Some dinosaurs were likely more behaviourally flexible than others. Some were probably fairly simple. Some may have been surprisingly sophisticated. Most were probably exactly as clever as they needed to be, which is more than can be said for many committee meetings.
And we can say that birds force us to take dinosaur cognition seriously.
Not romantically.
Seriously.
The surviving dinosaurs are not stupid. They are singing, caching, navigating, problem-solving, socially manipulating little theropods that occasionally steal chips.
That should make us cautious about underestimating the dead ones.
What We Do Not Know
Now for the annoying bit.
We do not know whether dinosaurs felt grief in a way we would recognise.
We do not know whether they played in a psychologically rich sense, though play-like behaviour is plausible in some lineages by comparison with living animals.
We do not know whether they formed individual attachments that were emotionally deep rather than behaviourally functional.
We do not know whether a dinosaur could miss another dinosaur.
We do not know whether a predator experienced frustration, satisfaction, anticipation, or anything close to what a mammal might feel in a hunt.
We do not know whether a crested dinosaur saw its reflection in water and thought, “Honestly, stunning.”
Probably not.
But the uncertainty is not a failure. It is the discipline.
The psychology of extinct animals requires intellectual humility. There is a difference between inference and fan fiction. A fossil can support a behavioural claim. It cannot support a Pixar monologue.
That does not make the subject less interesting. It makes it more interesting.
Because the real work is not inventing dinosaur feelings. It is asking what kinds of behaviour could plausibly emerge from a particular body, brain, ecology, and evolutionary history.
Simply Put
There is something quietly moving about this.
Dinosaurs are usually treated as spectacle: monsters, giants, skeletons, toys, logos, lunchboxes, cinematic inconveniences. But behaviour makes them stranger and more alive.
Not alive in the resurrected theme park sense. Please, no. We have suffered enough as a species.
Alive in the sense that they were not simply anatomical objects. They moved through worlds. They found food. They avoided danger. They reproduced. Some nested. Some gathered. Some displayed. Some fought. Some healed. Some followed others. Some died together. Some left footprints beside one another, and then time did the rest.
Psychology, at its best, is the study of organisms trying to make it through their worlds.
Dinosaurs did that for over 160 million years.
The tragedy is that we arrived too late to watch them.
The consolation is that they left marks.
A nest in stone.
A path through mud.
A skull shaped around vanished senses.
A living bird on a fence, screaming with all the dignity of an ancient lineage that survived the apocalypse and still wants your sandwich.
The extinct do not give interviews.
But they do leave traces.
And sometimes, if we are careful enough, those traces begin to look like behaviour.
References
Benton, M. J. (2010). Studying function and behaviour in the fossil record. PLoS Biology.
Natural History Museum. Why are birds the only surviving dinosaurs?
Natural History Museum. Were dinosaurs good parents?
Natural History Museum. How dinosaurs evolved into birds.
Royal Society Biology Letters. Dinosaur palaeoneurology: an evolving science.
RSPB. Birds: they’re small flying dinosaurs.
University of Reading. Dinosaur tracks show first evidence of multispecies herding.
Table of Contents
