Vallortigara, Giorgio (2017) Sentience does not require “higher” cognition. Animal Sentience 17(6)
Lori Marino, The inconvenient truth about thinking chickens
I agree with Marino (2017a,b) that the cognitive capacities of chickens are likely to be the same as those of many others vertebrates. Also, data collected in the young of this precocial species provide rich information about how much cognition can be pre-wired and predisposed in the brain. However, evidence of advanced cognition — in chickens or any other organism — says little about sentience (i.e., feeling). We do not deny sentience in human beings who, because of cognitive deficits, would be incapable of exhibiting some of the cognitive feats of chickens. Moreover, complex problem solving, such as transitive inference, which has been reported in chickens, can be observed even in the absence of any accompanying conscious experience in humans.