Abstract

Identifying which nonhuman animal species are capable of feeling pain is important both for understanding pain mechanisms more generally and for informing animal welfare regulations, particularly in genera that are not yet widely protected. A common way to try to provide evidence of pain experiences is through behavioral indicators. In this paper I use a very simple interventionist approach to experimentation, and the contrast case provided by C. elegans, to argue that behavioral indicators commonly used for identifying pain in nonhuman animals are much less robust than typically presented. Indeed, I argue that many behavioral indicators of pain are invalid as they are currently described. More positively, this analysis makes it possible to identify what valid criteria might look like, and where relevant, to identify existing evidence related to them. Based on this I propose that the best way to make progress on questions around animal pain is to clearly ally them with questions about animal consciousness more generally, and to productively use conceptual and empirical work in both areas to develop more theoretically defensible behavioral indicators.