In 2012, scientists from all walks of life, including the famous physicist Stephen Hawking, spoke with one voice to say that animals were endowed with consciousness. In their Cambridge Declaration on Consciousness , they affirmed that “humans are not the only ones to possess the neurological substrates that produce consciousness.” Since then, studies on animal cognition have flourished.
A book, published on October 18, 2018 by Editions Quae , proposes to take stock of the question of the consciousness of animals. It summarizes the results of a multidisciplinary expertise of INRA, which was conducted at the request of the unit “health and animal welfare” of the European Food Safety Authority ( EFSA ).
These results were presented in May 2017 to members of the European Animal Welfare Network. The full report was published in English in April 2017 (a summary in French is available on the INRA website ).
For this expertise, INRA mobilized 17 French researchers from various disciplines – biologists, philosophers, sociologists and lawyers. They conducted a review of the international literature, retaining in the end 659 references. The analysis of these texts and their unpublished synthesis presented in this book will allow readers to take stock of this complex issue.
A new approach to consciousness
To carry out this work, it was first necessary to take up the notion of consciousness in human beings, taking into account the recent contributions of neurobiology (see in this respect the book of the neuropsychologist Antonio Damasio, The Strange Order of things, life, feelings and the fabric of culture ) in this area.
The definition of consciousness retained in the book is as follows: it is a “subjective experience of the individual of the environment, his body and his own knowledge”, conferring on him an ability to perceive the world and solve problems.
Consciousness is classically presented under two components: the level and the content of consciousness. The level of consciousness refers to states of alertness, ranging from coma to awakening. The content of consciousness concerns the subjective perception of the environment and of oneself, and the evaluation and control of mental states.
To implement this awareness, different interacting nerve structures are associated with a central core, responsible for managing the rules of biological rhythms as well as vigilance. They allow for sometimes complex cognitive skills such as attention, learning, memorization, emotions and situational assessment. A single stimulus can activate many of these structures, but their interactions produce interpretations, intentions, and cause conscious actions.
The result of these interactions is of greater complexity than would be allowed by the sum of the activations of these different structures. It is this emergent property that constitutes consciousness.
What recent studies tell us
Recent studies, consulted as part of this multidisciplinary expertise , allow us to question certain statements about animals’ inability to be aware of themselves, to evaluate their knowledge or to remember.
Available studies on behaviour, cognition and neurobiology thus tend to show the existence of elaborate contents of consciousness in some animals, including mammals and birds. To illustrate these contents, the authors have chosen to develop different facets of the components of consciousness including emotions, metacognition, time control, social behavior and interactions with humans.
The ability to assess one’s own knowledge, also known as “metacognition,” was still recently considered a higher-level skill found only in humans. The new experimental devices and neurobiological developments have allowed, after Smith’s work on dolphins , to show that this skill also exists in several species of terrestrial mammals (monkeys, rodents) or marine mammals (dolphin) and birds (pigeon) .
The belief that animals were “stuck” in the present has also long been assumed. However, in some birds and mammals, it has been shown that there is an episodic memory that allows the animal to remember specific episodes, an assumed human capacity only. Finally, experiments show that animals can plan their future activities. The tayra ( Eira barbara ), a mustelid from Central and South America, for example hides green plantains and comes to pick them once they have matured.
The relationships of animals with each other and with humans are extremely flexible, allowing adaptation to multiple situations. For example, jays and gray squirrels have strategies to protect their cache by confusing tactics, using dummy caches that vary by audience.
Finally, the individual has the notion of his partners and their reactions: it is a “theory of the mind”, which characterizes the ability to attribute mental states to other individuals. Forms of empathy, one thinks of rats releasing a congener from his cage, and deception, giving for example false information to congeners, have on the other hand been observed in animals.
A search field that opens
In the context of this interdisciplinary expertise, defining the functional role of this animal consciousness was also necessary: the latter seems to allow responses adapted to the different situations and is probably the result of adaptations specific to the environments in which animals evolve.
This consciousness exists in many species with variable characteristics, ranging from a form of consciousness limited to a few elements in some invertebrates to a complex consciousness, observed in great apes but also in mammals and birds. However, it has not been demonstrated that this capacity covers all the skills that are characterized in humans.
This synthesis of the current work published on animal consciousness has made it possible to propose lines of research to fill the gaps in this area. Today, knowledge is still fragmentary and is based on too few species.
Better knowledge of the mental universe of animals could help to suggest ways to improve their welfare in the breeding conditions and advance the ethical reflection on livestock.