Developmental and Cross-Cultural Evidence for Intuitive Dualism

Humans may intuitively be dualists, imagining physical bodies and non-physical minds as distinct and separable. Intuitive dualism has been invoked to explain diverse phenomena, including the spread and distribution of religious beliefs and our intuitions about psychological illnesses. Alternatively, dualism may be learned gradually by participation in cultures with a Cartesian intellectual tradition. To compare these two explanations we collected data about which they make different predictions: the developmental trajectories and cultural variability of people’s proclivity to offer dualist interpretations of ambiguous stimuli. 180 Canadian children (aged 2-10 years), 42 Fijian children (aged 5-13) and 38 Fijian adults (aged 27-79) from a small village on a remote Fijian island, interpreted an ambiguous animation which may have depicted a mind switching bodies. Agency cues—proximity between the bodies and the transfer of salient eyes—shifted the proportion of participants offering dualist interpretations of the animation from 10% to 70%. Participants’ age and sex had no significant effect. Fijians with more Western education actually offered fewer dualist interpretations. Statistical models which assume that dualist interpretations ‘emerge early and everywhere’ fit our data far better than those which assume that dualism ‘develops gradually with exposure to Western cultural traditions’. A dult humans behave in peculiarly “dualist” ways. Adults everywhere profess beliefs in souls and the afterlife (Atran & Norenzayan, 2004; Boyer, 2001), mindless bodies (zombies), bodiless minds (ghosts, spirits) and minds entering new bodies (Cohen, 2007; Cohen & Barrett, 2008) and place unusual value on “genuine” artifacts (Bloom, 2005) as though they’d become infused with their owners’ non-physical essence. Even medical professionals show reasoning biases when thinking about ‘psychological’ versus ‘physical’ disorders(Ahn et al., 2009). Cross-cultural research suggests that adults’ intuitions about disembodied minds are strikingly similar across societies (Cohen et al., 2011). Young children sometimes expect minds to persist after their body dies (Astuti & Harris, 2008; Bering & Bjorklund, 2004). Both children (Notaro et al., 2001; Schulz et al., 2007) and adults (Ahn et al., 2009) struggle to draw causal connections between mindand body-related phenomena. Recent cognitive-historical work even indicates dualist thinking in ancient Chinese texts (Slingerland & Chudek, 2011). Since minds are not actually separable from bodies, the ubiquity of dualist beliefs is a scientific puzzle. Here we empirically arbitrate between two plausible explanations: intuitive and culturally acquired dualism. Intuitive Dualism (ID): Perhaps something about human minds causes them to reliably, with minimal cultural input, parse the world into two separate (and potentially separable) kinds of stuff: mental and physical