Ability to experience sensory stimuli and interpret it as aversive is insufficient. They don’t have the capacity to have emotional valence on top of those aversive stimuli, they don’t have emotions, they don’t care for themselves or others.
Can you elaborate on what you think is required for emotional valence and emotions? And why you don’t think invertebrates have that?
This could be a crux here.
I think it’s reasonably likely that many invertebrates, including fruit flies, have states worth describing like fear/anxiety and anger (driving aggression), and hence some states worth describing as emotions. Rethink Priorities also cited a study of a depression-like state in fruit flies:
Ries, A.-S., Hermanns, T., Burkhard Poeck, & Strauß, R. (2017). Serotonin modulates a depression-like state in Drosophila responsive to lithium treatment. Nature Communications, 8(1). https://doi.org/10.1038/ncomms15738
(EDITED)
Can you elaborate on what you think is required for emotional valence and emotions? And why you don’t think invertebrates have that?
This could be a crux here.
I think it’s reasonably likely that many invertebrates, including fruit flies, have states worth describing like fear/anxiety and anger (driving aggression), and hence some states worth describing as emotions. Rethink Priorities also cited a study of a depression-like state in fruit flies:
Ries, A.-S., Hermanns, T., Burkhard Poeck, & Strauß, R. (2017). Serotonin modulates a depression-like state in Drosophila responsive to lithium treatment. Nature Communications, 8(1). https://doi.org/10.1038/ncomms15738
See also the table here from RP’s more recent moral weight work.