Optimism about Measuring Animal Feelings

Asian Bioethics Review https://doi.org/10.1007/s41649-023-00244-7 PERSPECTIVE Optimism about Measuring Animal Feelings Heather Browning1 · Walter Veit2 Received: 18 October 2022 / Revised: 7 February 2023 / Accepted: 7 February 2023 © The Author(s) 2023 Abstract While animal sentience research has flourished in the last decade, scepticism about our ability to accurately measure animal feelings has unfortunately remained fairly common. Here, we argue that evolutionary considerations about the functions of feelings will give us more reason for optimism and outline a method for how this might be achieved. Keywords Animal sentience · Animal pain · Animal welfare · Animal ethics · Consciousness studies Animal sentience research has come to grown into something like a new discipline within the last decade. Yet, scepticism about our capacity to measure animal feelings has remained a widespread position. In a recent review of the field, Rowan et al. (2021) have provided a thorough analysis of the history of the concept of sentience, and its use in policy and animal advocacy, though noting that we are inevitably faced with uncertainty regarding the subjective states of other animals. As we shall argue, however, their fears are overblown. Here, we add a suggestion we think might strengthen the discussion on feelings and welfare assessment. Drawing on evolutionary considerations about the functions of feelings will give us more reason for optimism and our goal here will be to outline an approach for how we could measure animal feelings. Like Rowan et al. (2021), we agree that animal welfare consists in the feelings of animals – the positively and negatively valenced mental states that are consciously experienced (see Browning 2020 for a defence of this welfare concept). But while the authors think that research into animal feelings ‘brings with it a huge, almost insurmountable problem, which is that it is very difficult (and maybe impossible) to prove conclusively that any organism is sentient. Subjective feelings are just * Walter Veit 1 University of Southampton, Southampton, UK 2 University of Bristol, Bristol, UK 13 Vol.:(0123456789) Asian Bioethics Review that— subjective—and are available only to the animal (or human) experiencing them’ (p.5), we contend that there is reason for more optimism. We agree that measuring subjective feelings may be difficult, but not that this creates an insurmountable problem. After all, animal welfare science has spent a good part of the last two decades moving towards studying these experiences. The study of animal emotions is well-established (e.g. Désiré et al. 2002; Mendl and Paul 2004; Kremer et al. 2020), but the primary difficulty is still in distinguishing conscious, or felt, emotions, from the unconscious – a problem that has led some researchers to abandon the project entirely, in favour of other methods of assessing welfare (Dawkins 2021). However, we think there are ways to make progress on this question. While it is true that feelings are subjective, we should expect them to have detectable causal effects that make a difference to lives of sentient creatures. As the authors rightly note, animal feelings have evolved to play a role in animals’ lives, i.e. by providing a fitness benefit (examples of plausible accounts can be found in Dawkins 1998; Fraser and Duncan 1998; Veit 2022a, 2023). However, if Rowan et al. accept the common view that sentience provides animals with an evolutionary advantage, this would only have been possible if the presence of these feelings changes the animals’ phenotype in some way that is ‘visible’ to selection, for it is only actual causal impact of consciousness that could increase the survival and reproduction of such organisms such that we could think of consciousness as something that gradually evolved over evolutionary time. Such a view rules out the possibility of the feelings being epiphenomenal, i.e. a causally inefficacious by-product of other cognitive processes. This is important because natural selection does not invest in complex traits that have no adaptive function. If we think of consciousness as a mere by-product of cognitive processing, we would be unable to make sense of its obvious fit to the external (and internal) world in addition to its role in decision-making. If subjective experiences have causal effects, however, then – at least in theory – we will be able to study and measure them. Adding the term ‘subjective’ to experiences may give off the impression that they are somehow distinct from the apparent ‘objective’ reality that the sciences investigate, but there is no such a thing as a magical boundary that divides the world of the material from the mental (see also Veit 2022b). We should not give in to these kinds of arguments that are sometimes used to undermine the objectives of animal ethics, legislation, and welfare science. Thus, the question shifts from if to how and should alleviate the scepticism that we will never be able to know even approximately what the experience of other animals is like. This isn’t to deny that animal consciousness is hard to study, but that there isn’t something mysterious about the phenomenon of subjective experience that makes it wholly unique from other phenomena that are hard to investigate. Once we start building on the assumption that we can find ways of studying animal feelings by looking for the causal effects, we can broaden our empirical toolkit. Sceptics sometimes use slogans like one cannot infer a mental state from behaviour, but we have to distinguish between the claim that we can have absolute certainty about the experiences of others and the claim that no matter how much we learn about the brains, evolutionary history, and physiology of another animal that 13 Asian Bioethics Review we cannot have any confidence about their mental states when confronted with a particular behaviour such as withdrawal from a needle or jumping behaviour when confronted with a new toy. No one is claiming that we can have certainty about the experiences of other animals. That is simply not how science works. Misattributions of feelings are possible without thereby implying that the entire field of research rests on mistaken assumptions. More evidence will increase our certainty about the possibility of feelings in different species as well as about what their actual experiences consist in. Animal feelings will produce a range of detectable changes in neural processes, physiological functioning, and behaviour. Rowan et al. (2021) list a couple of approaches within the behavioural domain, including preference and motivation testing, and vocalisations. Beyond just the testing of how aversive (or pleasurable) an animal finds an experience, we may have means of assessing some of the qualitative features of these experiences – what it is like for the animal. We can develop tools for the identification of the presence and strength of differe (...truncated)