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Full-Text Articles in Zoology

Limits To Sentience, Donald M. Broom Jun 2023

Limits To Sentience, Donald M. Broom

Animal Sentience

There are many parallels between cellular function in animals and plants. Plants can have complex interactions with their environments. But they lack a central nervous system, which is a prerequisite for sentience (the capacity to feel). In my view the suggestion that plants are sentient is not only empirically incorrect but potentially harmful to the efforts to protect the welfare of sentient beings.


What Can Plant Science Learn From Animal Nervous Systems?, Luiz Pessoa Apr 2023

What Can Plant Science Learn From Animal Nervous Systems?, Luiz Pessoa

Animal Sentience

I welcome Segundo-Ortin & Calvo’s (2023) call for a rigorous science of plant behavior and physiology. My commentary addresses three points drawn from the literature on animal brains that could help elucidate the possibility of cognition and sentience in plants: (1) the presumed requirement of a centralized brain; (2) centralization of control versus heterarchical organization; and (3) connecting plant research with research on animal nervous systems.


Insentient “Cognition”?, Stevan Harnad Mar 2023

Insentient “Cognition”?, Stevan Harnad

Animal Sentience

A sentient state is a state that it feels like something to be in. Cows have them, cars don’t. Cognitive capacities are a subset of behavioral capacities. Not all behavioral capacities are cognitive (but the distinction is fuzzy). Might the difference have something to do with whether the behaver is sentient?


Animal Sentience Science And Policy, Andrew Crump Jan 2022

Animal Sentience Science And Policy, Andrew Crump

Animal Sentience

Animal sentience research cannot be divorced from its ethical and political implications. For example, discovering which animals are sentient is vital for deciding which require welfare protection. Two legal case-studies illustrate the importance of scientists in such debates: the UK Animal Welfare (Sentience) Act 2022 had input from animal sentience researchers, whereas the US Animal Welfare Act 1966 did not. The former defined sentient animals much more plausibly than the latter. I accordingly argue that sentience researchers should inform policy, and that this is achievable without sacrificing scientific integrity.


Fine-Tuning The Criteria For Inferring Sentience, Culum Brown Jan 2022

Fine-Tuning The Criteria For Inferring Sentience, Culum Brown

Animal Sentience

“Sentience” means the capacity to feel, and feelings are private affairs. Sentience is hence extremely difficult to quantify in nonhuman animals. We have no direct means of determining whether an animal is sentient. Thus we rely on a series of indirect measures or criteria which collectively provide some level of confidence about the probability that an animal is sentient. Crump et al. propose a modified framework based on 8 criteria for estimating the likelihood of sentience in a target taxon. Whereas I very much like their proposed framework, I would suggest a couple of amendments that may improve it further: …


Time To Stop Pretending We Don’T Know Other Animals Are Sentient Beings, Marc Bekoff Jan 2022

Time To Stop Pretending We Don’T Know Other Animals Are Sentient Beings, Marc Bekoff

Animal Sentience

Rowan et al.’s target article is an outstanding review of some of the history of the science of sentience, but one would have liked to see a much stronger “call to action.” We don’t need any more data to know that many other animals are sentient beings whose lives must be protected from harm in a wide variety of contexts. It is not anti-science to want more action on behalf of other animals right now.


Sentience In Decapod Crustaceans: A General Framework And Review Of The Evidence, Andrew Crump, Heather Browning, Alex Schnell, Charlotte Burn, Jonathan Birch Jan 2022

Sentience In Decapod Crustaceans: A General Framework And Review Of The Evidence, Andrew Crump, Heather Browning, Alex Schnell, Charlotte Burn, Jonathan Birch

Animal Sentience

We outline a framework for evaluating scientific evidence of sentience, focusing on pain experience. It includes eight neural and cognitive-behavioural criteria, with confidence levels for each criterion reflecting the reliability and quality of the evidence. We outline the rationale for each criterion and apply our framework to a controversial sentience candidate: decapod crustaceans. We have either high or very high confidence that true crabs (infraorder Brachyura) satisfy five criteria, amounting to strong evidence of sentience. Moreover, we have high confidence that both anomuran crabs (infraorder Anomura) and astacid lobsters/crayfish (infraorder Astacidea) meet three criteria—substantial evidence of sentience. The case is, …


All Living Organisms Are Sentient, Arthur S. Reber, Frantisek Baluska, William B. Miller Jr. Jan 2022

All Living Organisms Are Sentient, Arthur S. Reber, Frantisek Baluska, William B. Miller Jr.

Animal Sentience

We argue that all living organisms, from the simplest unicellular prokaryotes to Homo sapiens, have valenced experiences—feelings as states of preference—and are capable of cognitive representations. Bacteria can learn, form stable memories, and communicate, hence solve problems. Rowan et al.'s statement that "Subjective feelings are just that — subjective — and are available only to the animal (or human) experiencing them" is true but irrelevant. When we see a fish flopping about in the bottom of a boat we immediately recognize suffering without having a glimpse of the nature of piscine distress. Some controlled anthropomorphism can go a …


Legal Recognition Of Animal Sentience: The Case For Cautious Optimism, Jane Kotzmann Jan 2022

Legal Recognition Of Animal Sentience: The Case For Cautious Optimism, Jane Kotzmann

Animal Sentience

Rowan et al.’s target article provides a valuable indication of the work that was required to reach the point where animals are recognised as sentient in various laws. To ensure this work was not in vain, the language of sentience needs to be used as a moral currency to demand further cultural change involving greater human respect for animals.


The Science Of Animal Sentience And The Politics Of Animal Welfare Should Be Kept Separate, Marian Stamp Dawkins Jan 2022

The Science Of Animal Sentience And The Politics Of Animal Welfare Should Be Kept Separate, Marian Stamp Dawkins

Animal Sentience

Although linked historically by Rowan et al., the scientific study of animal sentience and political campaigns to improve animal welfare should be kept separate, for at least two reasons. First, the separation makes it clear that standards of evidence acceptable for ethical or political decisions on animal welfare can be lower than those required for a rigorously scientific approach to animal sentience. Second, it helps to avoid confirmatory bias in the form of giving undue weight to results that are in line with pre-conceived ideas and political views.


Revisiting Donald Griffin, Founder Of Cognitive Ethology, Carolyn A. Ristau Jan 2022

Revisiting Donald Griffin, Founder Of Cognitive Ethology, Carolyn A. Ristau

Animal Sentience

Donald Griffin’s writings, beginning with The Question of Animal Awareness (1976), strove to persuade scientists to study the possibility of animal sentience, the basis of Rowan et al.’s efforts to promote animal well-being. Facing great hostility (but also some acceptance) for his ideas, Griffin initially avoided animal welfare advocacy, fearing it would further undermine his efforts to gain recognition of animal sentience. In later years, however, he began to ponder the ethical implications of animal sentience, intending to study wild elephants’ communication and social behavior to better understand their experienced life and apply it to improving conservation methods. As he …


Pain Sentience Criteria And Their Grading, Eva Jablonka, Simona Ginsburg Jan 2022

Pain Sentience Criteria And Their Grading, Eva Jablonka, Simona Ginsburg

Animal Sentience

On the basis of the target article by Crump and colleagues, we suggest a more parsimonious scheme for evaluating the evidence for sentience. Since some of the criteria used by Crump et al. are not independent and some are uninformative we exclude some criteria and amalgamate others. We propose that evidence of flexible learning and prioritization, in conjunction with relevant data on brain organization, is sufficient for assigning pain-sentience to an animal and we suggest a scoring scheme based on four criteria.


Free Will And Animal Suicide, Sabina Schrynemakers Jan 2022

Free Will And Animal Suicide, Sabina Schrynemakers

Animal Sentience

David Peña-Guzmán presents two arguments against the view that because only humans have free will only humans can commit suicide: (1) nonhuman animals may possess free will, and (2) the libertarian notion of free will is incompatible with scientific explanation. The free will objection to animal suicide is indeed mistaken, but Peña-Guzmán’s criticism of the libertarian notion of free will seems misplaced. His target should instead be the assumption that free choices must be made consciously or self-reflectively or the assumption that freedom cannot come in degrees.


Truly Minimal Criteria For Animal Sentience, Mark Solms Jan 2022

Truly Minimal Criteria For Animal Sentience, Mark Solms

Animal Sentience

The criteria for determining animal sentience proposed in the target article are sensible but they lack an explicit functional justification for the focus on pain. This commentary provides an abbreviated account of the most basic functional principles that underpin animal sentience and articulates some minimal criteria for determining its presence.


Sentience In Decapods: Difficulties To Surmount, Michael L. Woodruff Jan 2022

Sentience In Decapods: Difficulties To Surmount, Michael L. Woodruff

Animal Sentience

In the target article Crump et al. present 8 criteria to assess whether decapods experience pain. Four of these -- sensory integration, motivational trade-offs, flexible self-protection, and associative learning -- could be used to assess sentience in general. In this commentary I discuss difficulties with using these criteria to provide evidence of sentience in decapods, particularly if this evidence is to change public opinion and policies. These difficulties are lack of evidence, the potential to eventually explain the neurobiological basis of the behaviors chosen as criteria, thereby eliminating any explanatory work for sentience, and the reluctance to bring animals that …


Distinguishing Epistemic And Moral Grounds For Legal Protection, Carlos Montemayor Jan 2022

Distinguishing Epistemic And Moral Grounds For Legal Protection, Carlos Montemayor

Animal Sentience

The criteria proposed by Crump et al. are based on various cognitive roles associated with sentience. A subset of them may be sufficient for certain kinds of welfare, but the presence of all of them should be considered as clearly sufficient for substantial kinds of legal protection based on their relation to capacities that we consider essential for moral standing in human beings.


Does The Sentience Framework Imply All Animals Are Sentient?, Kristin Andrews Jan 2022

Does The Sentience Framework Imply All Animals Are Sentient?, Kristin Andrews

Animal Sentience

The eight criteria proposed in Crump et al.’s framework for evaluating pain sentience in decapod crustaceans are just the tip of the iceberg when it comes to markers that could increase confidence in an animal’s sentience more generally. Some of the commentaries have already pointed out that pain is only one kind of sentience (Souza Valente). It has also already been pointed out that there are other criteria for pain that could be usefully added to the framework’s eight (Burrell). This expansive thinking about criteria that can be used to increase confidence in sentience raisess the question: in an expansive …


Sentience In Decapods: An Open Question, Mark Briffa Jan 2022

Sentience In Decapods: An Open Question, Mark Briffa

Animal Sentience

Crump et al.’s framework is a powerful tool designed to assist decisions on the ethical treatment of decapod crustaceans. However, the question of whether decapods are sentient (i.e., whether they feel), remains open, perhaps indefinitely. More optimistically, we might design experiments that distinguish among different levels of awareness, sometimes viewed as components of sentience. We should strike a balance between assuming that all organisms are sentient and making unnecessary anatomical assumptions about sentience. Refining current experiments may provide concrete insights about awareness in Decapoda and other taxa.


Sentience As Part Of Emotional Lives, Frans B. M. De Waal Jan 2022

Sentience As Part Of Emotional Lives, Frans B. M. De Waal

Animal Sentience

It is high time to explore the sentience of invertebrate animals, but this topic cannot be discussed without also exploring their emotional lives, including positive emotions. Sentience probably evolved to allow the regulation of emotions by endowing them with feelings.


Pros And Cons Of A Framework For Evaluating Potential Pain In Decapods, Robert W. Elwood Jan 2022

Pros And Cons Of A Framework For Evaluating Potential Pain In Decapods, Robert W. Elwood

Animal Sentience

The rigorous framework for research into potential pain in decapods was successful in allowing legislators in the United Kingdom to evaluate a complex scientific issue. However, it might produce problems for research. I discuss doubts about the usefulness of the eight criteria. Some have yet to receive any investigation and others do not allow much inference about pain. In addition, some existing studies are not covered in the framework. Most worrying, however, is the potential for stifling future research of novel areas that are excluded from the framework.


Sentience Politics : A Fishy Perspective, Culum Brown Jan 2022

Sentience Politics : A Fishy Perspective, Culum Brown

Animal Sentience

The plight of fishes has almost certainly got worse since Bentham (1789) coined the phrase “The question is not Can they reason? nor, Can they talk? but Can they suffer?” Despite the fact that fishes are increasingly recognised as sentient animals worthy of protection under animal welfare legislation in many countries around the world, fishing practices are almost universally exempt activities. The human population continues to grow, and, surprisingly, per capita intake of fish is still increasing (FAO 2020). The source of this fish is not wild stocks (catches of which have remained more or less stagnant for …


The Reality And Prevalence Of Animal Sentience, Antonio Damasio Jan 2022

The Reality And Prevalence Of Animal Sentience, Antonio Damasio

Animal Sentience

Rowan et al use findings from neurobiology, clinical neurology, and general biology to argue for the extensive presence of sentience in animals, but they are wisely cautious concerning when in the phylogenetic scale that emergence occurred.


Motivated Science: What Humans Gain From Denying Animal Sentience, Uri Lifshin Jan 2022

Motivated Science: What Humans Gain From Denying Animal Sentience, Uri Lifshin

Animal Sentience

Resistance to the idea that non-human animals are sentient resembles erstwhile resistance to the theory that the earth is not the centre of the universe, or that humans evolved from “apes”. All these notions are psychologically threatening. They can remind people of their own creatureliness and mortality and might make them feel guilty or uncertain about their way of life. An honest debate over animal sentience, welfare and rights should consider the human motivation to deprive animals of these things in the first place. I briefly review empirical evidence on the psychological function of denying animal minds.


Why The Recognition Of Sentience Is So Important For Animal Welfare, Mark Jones Jan 2022

Why The Recognition Of Sentience Is So Important For Animal Welfare, Mark Jones

Animal Sentience

Rowan et al. (2022) provide a useful summary of the history and development of the philosophical, public, and legal recognition of animal sentience and its importance in improving the welfare of animals. Here I argue for the incorporation of the precautionary principle in sentience recognition, and the wider significance of sentience recognition to the current climate, biodiversity and human health crises.


Defending Human Difference By Raising The Bar, Joe Gough Jan 2022

Defending Human Difference By Raising The Bar, Joe Gough

Animal Sentience

Chapman & Huffman (C&H) offer a theory of why we humans want to believe that we are different: to justify our cruelty to animals. This commentary offers further supporting evidence of this and examines more closely what the claim that humans are ‘different’ amounts to. It also considers some methodological issues in animal psychology closely related to C&H ‘s theory. These problems result from a common strategy for defending hypotheses about human difference.


Extending Animal Welfare Science To Include Wild Animals, Walter Veit, Heather Browning Jan 2021

Extending Animal Welfare Science To Include Wild Animals, Walter Veit, Heather Browning

Animal Sentience

Ng’s (2016) target article built on his earlier work advocating a science of welfare biology (Ng 1995). Although there were problems with the models proposed in Ng’s original paper regarding the balance of pleasure and suffering for wild animals, his call for a science of wild animal welfare was a sound one. This does not require a new discipline but just an extension of the existing frameworks and methods of animal welfare science to include wild animals.


Consider The Agent In The Arthropod, Nicolas Delon, Peter Cook, Gordon Bauer, Heidi Harley Jul 2020

Consider The Agent In The Arthropod, Nicolas Delon, Peter Cook, Gordon Bauer, Heidi Harley

Animal Sentience

Whether or not arthropods are sentient, they can have moral standing. Appeals to sentience are not necessary and retard progress in human treatment of other species, including invertebrates. Other increasingly well-documented aspects of invertebrate minds are pertinent to their welfare. Even if arthropods are not sentient, they can be agents whose goals—and therefore interests—can be frustrated. This kind of agency is sufficient for moral status and requires that we consider their welfare.


Avoiding Anthropocentrism In Evolutionarily Inclusive Ethics, Simon Fitzpatrick Jul 2020

Avoiding Anthropocentrism In Evolutionarily Inclusive Ethics, Simon Fitzpatrick

Animal Sentience

Mikhalevich & Powell are to be commended for challenging the “invertebrate dogma” that invertebrates are unworthy of ethical concern. However, developing an evolutionarily inclusive ethics requires facing some of the more radical implications of rejecting hierarchical scala naturae and human-centered conceptions of the biological world. In particular, we need to question the anthropocentric assumptions that still linger in discussions like these.


Zones Of Precaution, Jonathan Birch Jul 2020

Zones Of Precaution, Jonathan Birch

Animal Sentience

My commentary focusses on Mikhalevich & Powell’s criticisms of the Animal Sentience Precautionary Principle. I emphasize the pragmatic nature of my rationale for proposing that, rather than extending the scope of animal welfare protection on a species-by-species basis, we should be willing to protect entire Linnaean orders on the basis of evidence from a single species.


Brain Complexity, Sentience And Welfare, Donald M. Broom Jul 2020

Brain Complexity, Sentience And Welfare, Donald M. Broom

Animal Sentience

Neither sentience nor moral standing is confined to animals with large or human-like brains. Invertebrates deserve moral consideration. Definition of terms clarifies the relationship between sentience and welfare. All animals have welfare but humans give more protection to sentient animals. Humans should be less human-centred.