Marino has provided an accurate and nuanced view about chickens' complex capabilities as sentient individuals. I explore the implications of these findings for scholars as well as for activists in the protection of farmed animals.
This commentary examines the next step in Marino's target article – changing people's attitudes and beliefs about chickens. The scientific case seems clear: chickens are far more complex, psychologically and socially, than originally thought. Marino suggests we use this information to make people feel uncomfortable about their dietary choices in the hope of changing them. We review the psychological literature, examining how people maintain meat consumption despite the clash with their moral beliefs (the "meat paradox"). This work highlights the important gap between what science knows about animals and what people think about animals.
Marino's target article provides an overview of chickens' cognition, emotion, and personality, with the aim of changing how people view chickens. In this commentary, I will agree that chickens deserve better than their reputation, but contend with a statement about the lack of behavioral change under chicken domestication.
Kujala (2017) presents an extensive overview of existing research on canine emotions in comparison to those of other non-human animals and humans. This commentary provides some additional research results on the intensively debated field of empathy in dogs. We focus on recent advances in the understanding of a fundamental building block of empathy — emotional contagion — and on dogs' remarkable sensitivity for human emotions, including the skills of assistance dogs.
Zentall suggests that the same mechanism underlies cognitive dissonance in humans and the within-trial contrast effect in pigeons (and humans). The contrast effect has face validity in explaining cognitive dissonance, but more research is needed to establish construct validity. To determine whether both phenomena share the same mechanism, future research should test (1) whether both share physiological processes, (2) whether individuals who show sensitivity to one are also sensitive to the other, and (3) whether both phenomena are affected by the same changes in an independent variable.
I respond to five commentaries on my 2016 book What a Fish Knows. The commentaries express more harmony than dissent about my interpretation of fishes as cognitive, aware individuals deserving better treatment by humankind.
Peña-Guzmán's target article on animal suicide will help inform end-of-life care for animals by emphasizing the need for a broad research focus on animal thanatology. Greater scientific understanding of the continuum of death-related awareness, experiences, and behaviors will help us improve veterinary care for animals at the end of life.
Key's (2016) target article provides some strong arguments but also makes some logical mistakes. The arguments are not sufficient to support a definite conclusion that fish cannot feel pain. A multi-faceted perspective taking into account brain structure, chemical secretion in brain, animal behavior, and evolutionary biology may be useful and appears, at least in some aspects, to suggest the opposite conclusion from that of the target article.
In his target article, Key (2016) reviews the neuroanatomy of human pain and uses what is known about human pain to argue that fish cannot experience pain. We provide three reasons why the conclusions reached by Key are unsupported. They consider (i) why it is not sufficient to conclude that only human neural structures can process conscious pain, (ii) why an understanding of pain in humans and non-human animals needs to be based within a framework of consciousness, and (iii) evidence already exists that fish treated with noxious stimuli lose the ability to perform normal behaviours: This was a behavioral proxy that Key proposed would provide good evidence for an animal to feel pain.
Although Key (2016) argues that mammals feel pain and fish do not, from an invertebrate perspective, it is obvious that the pain experience is shared by animals from a number of different animal groups.
I present a little-known example of flexible, opportunistic behavior by a species of fish to undermine Key's (2016) thesis that fish are unconscious and unable to feel. Lack of a cortex is flimsy grounds for denying pain to fish, for on that criterion we must also then deny it to all non-mammals, including birds, which goes against scientific consensus. Notwithstanding science's fundamental inability to prove anything, the precautionary principal dictates that we should give the benefit of the doubt to fish, and the state of the oceans dictates that we act on it now.
Key's (2016) discussion of his claim that fish do not feel pain ignores the history of attempts to study the attribution of mental states to other species. Although willing to accept that mammals feel pain, Key claims that fish lack the mammalian neural mechanisms underlying pain and are unconscious of their experiences. Consequently, we do not need to be overly concerned about fishing practices that would otherwise be viewed as painful. Key uses a flawed anthropomorphic lens. All attributions of mental events to organisms other than oneself involve inferences derived from anthropomorphic processes through which we process physiological and behavioral data. To do this effectively we need to employ a critical anthropomorphism incorporating our experiences as sentient beings along with diverse scientific findings, avoiding claims that some types of data always trump other considerations.
Yew-Kwang Ng's research is the work of an obviously sincere, intelligent, and conscientious animal advocate. But I am unable to accept his starting assumption that animal welfare is an appropriate basis for animal ethics. More specifically I argue that animal welfare as a means to animal liberation is an issue that can be debated, but animal welfare as the ultimate end or goal of animal advocacy is misguided.