Evidence for Sentience in Reptiles

Though we cannot directly assess consciousness in nonhuman animals, an increasing number of researchers are adopting the marker approach — amassing evidence of behaviours that may indicate consciousness to determine which species are likely to be conscious. Here, I review the evidence for behavioural markers of sentience (also sometimes called phenomenal consciousness) in reptiles, a historically understudied class. Reptiles show some evidence of experiencing pain, stress, and pleasure, demonstrate active sleep and open-ended associative learning, display complex social cognition, and appear capable of self-recognition. However, in all these areas, the behaviours considered key indicators of sentience have often not been tested. There is a need for much more research on all these behaviours and their mechanisms in a wider range of reptile species.