biostudies-literatureOstojic LMedical Research CouncilBiotechnology and Biological Sciences Research Council4123-8https://www.ebi.ac.uk/biostudies/studies/S-EPMC3593841biostudies-literatureUnknown110(10)State-attribution is the ability to ascribe to others an internal life like one's own and to understand that internal, psychological states such as desire, hope, belief, and knowledge underlie others' actions. Despite extensive research, comparative studies struggle to adequately integrate key factors of state-attribution that have been identified by evolutionary and developmental psychology as well as research on empathy. Here, we develop a behavioral paradigm to address these issues and investigate whether male Eurasian jays respond to the changing desire-state of their female partners when sharing food. We demonstrate that males feed their mates flexibly according to the female's current food preference. Critically, we show that the males need to see what the female has previously eatenProceedings of the National Academy of Sciences of the United States of AmericaEvidence suggesting that desire-state attribution may govern food sharing in Eurasian jays.PMC3593841BB/I000690/1Cheke LGOstojic LShaw RCClayton NSfalseEvidence suggesting that desire-state attribution may govern food sharing in Eurasian jays.State-attribution is the ability to ascribe to others an internal life like one's own and to understand that internal, psychological states such as desire, hope, belief, and knowledge underlie others' actions. Despite extensive research, comparative studies struggle to adequately integrate key factors of state-attribution that have been identified by evolutionary and developmental psychology as well as research on empathy. Here, we develop a behavioral paradigm to address these issues and investigate whether male Eurasian jays respond to the changing desire-state of their female partners when sharing food. We demonstrate that males feed their mates flexibly according to the female's current food preference. Critically, we show that the males need to see what the female has previously eaten2013-01-01T00:00:00Z2013 Mar2025-04-19T09:05:38.959Z2019-03-27T01:05:52ZS-EPMC35938412338218710.1073/pnas.1209926110