The nature of consciousness has long intrigued philosophers, scientists, and the general public alike. It raises profound questions about awareness, experience, and the very essence of being. Exploring whether consciousness is exclusive to humans or shared with other species challenges conventional thinking and requires rigorous scientific and philosophical inquiry.
Defining Consciousness and Its Dimensions
Jonathan Birch, a philosopher at the London School of Economics, emphasizes the difficulty in definitively identifying consciousness in others due to its inherently subjective nature. Birch refers to the framework of philosopher Herbert Feigl, who describes consciousness as layered in three parts: sentience, sapience, and selfhood.
Sentience is the basic sensation of the present moment, including external stimuli and internal feelings such as pain and pleasure. Sapience involves the capacity to reflect on these experiences, exemplified by thoughts like “This pain is the worst I’ve ever had.” The deepest layer, selfhood, is the awareness of oneself as an entity with a continuous past, present, and future.
Scientific Insights into Animal Consciousness
Research into animal consciousness has focused primarily on sentience. The ability to perceive pain is widely accepted among many species. For example, dogs can communicate distress to their owners, and fish have been observed to seek out painkillers in their environment, demonstrating awareness of discomfort.
Social behavior also provides significant evidence. Kristin Andrews, a philosopher at York University in Toronto, notes that animals acquire much of their knowledge and skills through social learning, a trait observed across diverse species, including insects. Fruit flies have been shown to learn mating preferences by observing others, highlighting the complexity of their interactions.
Additional studies have revealed episodic memory—the ability to recall past events—in species such as rats, scrub jays, and chimpanzees. This suggests a form of self-awareness and the capacity to mentally relive experiences.
Neurobiological Diversity and Consciousness
Understanding consciousness across species is complicated by the wide variety of neural structures. Mammalian brain regions linked to consciousness do not exist in the same form in insects or other invertebrates. Despite these differences, behavioral evidence supports the presence of sentience in species with vastly different neurobiology.
In 2024, the New York Declaration on Animal Consciousness was published, acknowledging a realistic possibility that many animals, including numerous invertebrates, possess conscious experience. This document represents a significant shift in scientific attitudes toward the cognitive capacities of non-human animals.
Kristin Andrews advocates for a baseline assumption that all animals have consciousness, challenging long-held scientific views that often excluded invertebrates from consideration. Jonathan Birch describes the historical dismissal of animal sentience as “an aberration of Western science,” contrasting it with many non-Western cultures that have recognized animal sentience for centuries.
