My overall conclusion is that chickens are just as cognitively, emotionally and socially complex as most other birds and mammals in many areas, and that there is a need for further noninvasive comparative behavioral research with chickens as well as a re-framing of current views about their intelligence.).
When asked to rate the typicality of chickens as a member of the more general category of birds, raters usually give chickens a low score indicating that they are not considered typical birds (Malt and Smith ).
Therefore, even considerations of birds in general may not apply very well to chickens.
In other studies, their welfare is ultimately related to productivity.
Far less numerous are studies of chickens on their own terms—as birds, within an evolutionary and comparative framework.
Yet, views of chickens have largely remained unrevised by this new evidence.
In this paper, I examine the peer-reviewed scientific data on the leading edge of cognition, emotions, personality, and sociality in chickens, exploring such areas as self-awareness, cognitive bias, social learning and self-control, and comparing their abilities in these areas with other birds and other vertebrates, particularly mammals.
Domestic chickens are members of an order, Aves, which has been the focus of a revolution in our understanding of neuroanatomical, cognitive, and social complexity.
At least some birds are now known to be on par with many mammals in terms of their level of intelligence, emotional sophistication, and social interaction.
Likewise, the brains of birds have historically been viewed as simpler and more primitive than those of mammals.
However, that assumption about avian brains has now been overturned by more recent studies showing that there are many functional similarities in the brains of birds and mammals, allowing for similar cognitive abilities.