Measuring Animal Welfare: Philosophical Foundations, Practical Indicators, and Overall Assessments
It is our aim at Animal Ask to support organisations with research in their ask prioritisation in order to improve the welfare of farmed animals.
A key component of this is evaluating and quantifying the effect of asks on the welfare of animals. Given this aim, we have spent the last few months researching the most reliable way to measure an animal’s welfare to support us in these efforts.
Our report provides a brief discussion surrounding the philosophical foundations of welfare and theories of well-being, an examination of the empirical research into the reliability and validity of indicators of animal welfare, and a review of existing overall welfare assessments.
This is a link post to https://www.animalask.org/research
EXECUTIVE SUMMARY
In this report, I examine animal welfare through three stages of analysis. The first is a philosophical discussion surrounding the definition of what animal welfare is and how this definition could differ qualitatively between different animals. This provides the foundation for further research as the validity of practical measures can only be tested with a concrete understanding of the underlying construct. Overall, we accept the definition presented by Bracke and Hopster (2006) that ‘Animal welfare is the quality of life as perceived by the animal itself’* but recognise that this still leaves many open questions. In our analysis, we place the most weight on the hedonic and then desire theories of well-being; these value positive and negative experiences or preferences respectively. The relative weight each reader may place on different theories of well-being in non-human animals may vary and should be considered in subsequent sections.
Once the concept of animal welfare has been more clearly defined, I then investigate the strength of different welfare indicators used in the scientific literature. These are the on the ground, testable attributes that one can use to assess the welfare of an individual. In non-human animals, these can be categorised into four clusters: preference tests, physiological indicators, physical health, and behavioural indicators. Each indicator within each category has its own strengths and weaknesses. However, preference tests are the strongest indicators on the whole as they more directly reflect the mental state of the animal. Although they are the easiest to measure, psychological indicators are the weakest measures as they vary depending on numerous other factors or are associated with both positive and negative valence experiences. Therefore, these should be taken in the context of many other indicators to create a holistic picture of the welfare of the individual.
Finally, the report concludes with an examination of current attempts to synthesise these indicators into an overall evaluation of animal welfare. These systems attempt to gather information on various indicators to provide an overall assessment of welfare. These include both the animal-based indicators examined in this report and environmental conditions. Every measure examined has numerous flaws so the results of each system should always be considered in light of its limitations. I argue that rather than relying on any given assessment the best solution is to use a combination of methods that rely on different techniques. The ideal system would use a combination of qualitative measures, expert opinion based measures, an index of animal-based measures, and standalone measures such as preference testing or qualitative behavioural assessment. This combination would provide a variety of qualitative and quantitative perspectives using information for a wide variety of indicators to guide decision making. In practice, where time constraints limit the extensiveness of our research a more limited combination may have to be used.
*It is worth noting that although this is what we perceive to be valuable for an animal’s well-being this does not constitute all we find morally valuable for prioritising asks. Other considerations include the probability of sentience (Open Philanthropy, 2018) the moral weight or the capacity for welfare of different species (Schukraft 2020). We are aware that given our moral uncertainty one ought to assign some value to other aspects of an animal’s life such as avoiding any violation of their rights. Although these are all important considerations in the wider debate about how we should treat animals, this is outside of the scope of this report.
To continue reading, please access the full report on our website via this link.
Hi George (presumably),
I found this report very helpful as someone who mostly thinks about measuring the well-being of humans. I think it lays things out nicely : philosophical foundations, then the types of measurement instruments, ending with a discussion of “state of the art” of what’s commonly used.
I also appreciate how the report lays out assessments of reliability, validity and interpersonal comparisons of utility for each class of welfare indicators. However, I think a reader like myself would feel more oriented if each section concluded with a summary assessment of the measure.
This is obviously difficult. Ideally we’d have some sort of model like
wellbeingmeasured=accuracy∗importance=(reliability∗cardinality)∗(validity∗wellbeingaccount)
Where we just plug in values 0-1 into each parameter and presto get the best measures—but I’m not sure if that’s coherent.
It only seemed like I got a sense of your overall judgement in the executive summary and somewhat in the concluding discussion. And for this overall judgement I would have enjoyed reading more reasoning (like how much better are physical health and behavioral indicators than physiological indicators?)
You say:
But I’m not sure I follow. Would the ideal system use a combination? I think the ideal system would have a single measure that perfectly tracks what matters, no? Could you explain what you’re thinking here?
My last question is: what are y’all’s thoughts on making across species comparisons? This is the question that really interests me, and most of these indicators presented seem to be much, much more suitable to within species assessments of welfare.
Please keep up the great work!
Hello Joel,
I agree that in hindsight a summary of each indicator would probably have been useful to provide the reader with an overall assessment given the information I reviewed in the report.
That model is roughly the way I was thinking of this assessment, with validity and interpersonal comparisons being how much I would update on a perfectly accurate measure, and reliability giving some sense how wide the confidence interval would be from a real world measurement. The trade off of these, between groups of indicators and individual indicators, adds some nuance so that a single physiological measure is reliable but can vary due to numerous other factors but a combination of them allows us to measure the welfare benefit of things that health can’t capture easily. For example, it may be better to minimise disease rates instead of blood glucose levels if given no context but disease rates would be unable to assess the importance of different types of environmental enrichment.
If more people comment to express interest in an overview of each section, I am happy to invest the time to go back through the report to add in these sections.
I definitely agree, which is partially why I put an example of self-reports in humans (which are in my opinion as close to ideal as we can get) alongside the measures we have available in other animals. This is what I currently view as the best available (‘ideal’) system given the weaker methods available.
In this context, many of these indicators struggle on cross species comparisons. Take cortisol for example, where different species have different cortisol levels, making it difficult to compare levels or even percentage changes across species. We can gain some sense of the relative importance of different improvements or events for an individual from the degree of change of an indicator. An example of this within an operant test could be a human showing a mild preference for social contact vs food compared to a fox who shows the opposite relationship. Yet, this still only gives us information within the range of their utility functions and doesn’t tell us how their ranges compare. It’s a challenging question and due to this we have mostly been deferring to Rethink Priorities’s work on moral weights and Open Philanthropy Project’s report on consciousness. At the moment, we approach this by using an assessment of an animal’s quality of life, to gauge how important an improvement is within an individual’s utility function, and then adjust this based on these considerations. However, I would be cautious about concluding that an ask is more promising if the deciding factors are based across species comparisons given the range of plausible views on the topic.
Thanks for the feedback
George,
You’re welcome. I’m excited to see what comes next!
Hi George,
I haven’t yet dug into the details, but I am very much looking forward to doing so. Thanks for doing great work and sharing it here!