How does consciousness vary across the animal kingdom? Are some animals 'more
conscious' than others? This article presents a multidimensional framework for …

The brains of animals show chemical, anatomical, and functional differences, such as
dopamine production and structure of sleep, between Amniota and older groups. In addition …

How consciousness appeared much earlier in evolutionary history than is commonly
assumed, and why all vertebrates and perhaps even some invertebrates are conscious …

In The Genesis of Animal Play, Gordon Burghardt examines the origins and evolution of play
in humans and animals. He asks what play might mean in our understanding of evolution …

Circadian rhythms influence most of our life activities, notably getting up and going to sleep
every day. The new edition of this book delves into the mechanisms surrounding how these …

Reptiles and amphibians have been neglected in research on cognition, emotions, sociality,
need for enriched and stimulating environments, and other topics that have been greatly …

Abstract In his book The Expression of the Emotions in Man and Animals, Charles Darwin
(1872/1965) defended the argument that emotion expressions are evolved and adaptive (at …

This paper presents arguments for, and evidence in support of, the important role of
pleasure in animals' lives, and outlines its considerable significance to humankind's …

This article introduces and defends the “pathological complexity thesis” as a hypothesis
about the evolutionary origins of minimal consciousness, or sentience, that connects the …

The recognition of animal pain and stress, once controversial, is now acknowledged by
legislation in many countries, but there is no formal recognition of animals' ability to feel …