Animal Cognition Testing: How We Measure Animal Intelligence & Sentience

How do scientists assess animal minds? Over the past century, and especially the last 40 years, a rich toolkit of behavioral paradigms has been developed to test animal cognition — from simple associative learning to theory of mind, episodic memory, and self-recognition. These tests reveal what animals can do, and increasingly, what animals experience.

Why Cognition Testing Matters for Welfare

The welfare implications of animal cognition are profound. Animals that can form memories of past suffering may experience prolonged negative states rather than only momentary pain. Animals that anticipate future negative events may suffer fear and anxiety before harm arrives. Animals with self-awareness may experience their situation in more complex ways. Cognition testing helps us understand these dimensions of animal experience — and design welfare standards accordingly.

Key Paradigms in Animal Cognition Research

Mirror Self-Recognition Test (MSR)

The classic test for self-awareness: an animal is anaesthetized, a visible mark is placed on its body, and it's observed when it wakes in front of a mirror. An animal that inspects the mark (rather than treating the reflection as another animal) demonstrates self-recognition — awareness that the reflection represents itself.

Passed by: Great apes (reliably), dolphins, elephants (some individuals), magpies, manta rays (recent evidence), cleaner wrasse fish (controversial)

Welfare link: Self-recognition implies a sense of self that may be compromised by captivity, social isolation, and loss of agency

Object Permanence Tests

Does an animal understand that an object continues to exist when hidden? Higher-order object permanence (Stage 6 — tracking invisible displacements) requires mental representation of absent objects.

Welfare link: Object permanence may underlie memory of past events and anticipation of future states — both relevant to welfare assessment

Episodic Memory Tests (What-Where-When)

Can an animal remember not just what happened, but where and when? "Scrub jay" experiments by Clayton and Dickinson showed these birds specifically re-cache food items they know will decay based on when they hid them — demonstrating episodic-like memory.

Passed by: Western scrub jays, chimpanzees, rats, pigeons, cuttlefish, and some octopuses

Welfare link: Episodic memory means animals may replay and be affected by past welfare-relevant experiences (fear, pain, confinement)

Cognitive Bias Tests

This paradigm tests emotional state rather than intelligence. Animals trained to respond differently to two stimuli (e.g., one tone signals food, another signals no food) are presented with an ambiguous intermediate stimulus. Animals in positive welfare states respond "optimistically" (expecting food), animals in negative states respond "pessimistically".

Used in: Pigs, rats, sheep, horses, dogs, bees

Welfare link: The most direct welfare application — this paradigm measures emotional state, not just behavior

Theory of Mind / Gaze Following

Does an animal understand that others have different mental states, beliefs, and perspectives? Tested through gaze following, false belief tasks, and tactical deception experiments.

Passed by: Great apes (partial), dogs (gaze following, some referential understanding), ravens, jays, domestic animals to varying degrees

Landmark Findings That Changed Our Understanding