Do you believe that aliens feel pain? An empirical investigation of mental state attributions

On what basis do we attribute phenomenal states to others? One answer, defended by John Stuart Mill, appeals to an analogy between ourselves and the similar bodies and actions of others (1865, p. 208). Despite its intuitive plausibility, this position is often rejected (Arico et al., 2011; Buckwalter & Phelan, 2014; Knobe & Prinz, 2008). In line with Mill’s account, we propose that the primary factors used when making phenomenal state ascriptions are the appropriate display of functional and behavioral cues and having bodies with the right kind of physical composition. To test this account, we gave five groups of participants a vignette followed by three to six questions. For four of the groups, the vignette described an alien-human encounter and the participants had to judge the likelihood (on a 7-point scale) that the alien had a non-phenomenal state (a belief) and the likelihood that it could have a phenomenal state (pain). The fifth group, as a control, read a vignette about a similar interaction between two humans. We found that, as appropriate functional and behavioral cues and then humanoid features are added to the alien, people are more willing to attribute a phenomenal state to it. Attributions of the non-phenomenal state are primarily dependent on the appropriate functional and behavioral cues, not on having humanoid features.