Although it is widely accepted that adult humans possess a ‘theory of mind’, debate has surrounded whether non-human animals may also be capable of attributing mental states such as knowledge, beliefs and desires to others. While researchers agree that animals are unlikely to possess a human-like theory of mind; theory of mind is now viewed as a continuum of social cognitive abilities and as such animals may possess limited elements of mental state attribution. A minimal form of theory of mind has been proposed by Apperly and Butterfill in human adults, which would allow rapid, efficient responses alongside a separate, slower, ‘full blown’ theory of mind. It has been suggested that this minimal system may be behind the limited theory of mind proposed in animals. Given that desires are representationally simpler than beliefs, desire attribution may be a good candidate for convergent minimal social cognitive abilities. In this thesis I therefore used Eurasian jays (Garrulus glandarius) as a comparator with human adults, due to existing evidence of Eurasian jays’ sensitivity to their partner’s desires. I focused on three key questions in my thesis:
1. Do adult humans have an implicit sensitivity to the desires and preferences of others?
2. Do Eurasian jays have a generalised sensitivity to others’ desires and preferences?
3. Are non-human animals’ responses to others’ desires and preferences comparable to adult humans’ implicit responses?
To address these questions I assessed adults’ implicit sensitivity to others’ desires in various scenarios, but did not find evidence of a consistent minimal system (Chapters 2, 3, 6). In addition, I investigated whether Eurasian jays’ sensitivity to the desires of others may be applied outside of the food sharing context, as well as the flexibility of this sensitivity within food sharing (Chapters 4-6). Finally, I considered the similarities between the responses of Eurasian jays and humans and discuss the consequences of these findings for the hypothesis of a shared minimal system. I conclude by discussing the difficulties facing comparative cognition research and the possibility that theory of mind may be overestimated as a driver of social interactions in both humans and non-human animals
