Dogs Mentally Represent Jealousy-Inducing Social Interactions.

Jealousy may have evolved to protect valuable social bonds from interlopers, but some researchers have suggested that it is linked to self-awareness and theory of mind, leading to claims that it is unique to humans. We presented dogs ( = 18; 11 females; age: = 4.6 years, = 1.

Contagious yawning is not a signal of empathy: no evidence of familiarity, gender or prosociality biases in dogs.

Contagious yawning has been suggested to be a potential signal of empathy in non-human animals. However, few studies have been able to robustly test this claim. Here, we ran a Bayesian multilevel reanalysis of six studies of contagious yawning in dogs.

Watching eyes do not stop dogs stealing food: evidence against a general risk-aversion hypothesis for the watching-eye effect.

The presence of pictures of eyes reduces antisocial behaviour in humans. It has been suggested that this 'watching-eye' effect is the result of a uniquely human sensitivity to reputation-management cues. However, an alternative explanation is that humans are less likely to carry out risky behaviour in general when they feel like they are being watched.

New Caledonian Crows Behave Optimistically after Using Tools.

Are complex, species-specific behaviors in animals reinforced by material reward alone or do they also induce positive emotions? Many adaptive human behaviors are intrinsically motivated: they not only improve our material outcomes, but improve our affect as well [1-8]. Work to date on animal optimism, as an indicator of positive affect, has generally focused on how animals react to change in their circumstances, such as when their environment is enriched [9-14] or they are manipulated by humans [15-23], rather than whether complex actions improve emotional state. Here, we show that wild New Caledonian crows are optimistic after tool use, a complex, species-specific behavior.