Is Optimism Optimal? Functional Causes of Apparent Behavioural Biases

We review the use of the terms ‘optimism’ and ‘pessimism’ to characterize particular types of behaviour in non-human animals. Animals can certainly behave as though they are optimistic or pessimistic with respect to specific motivations, as documented by an extensive range of examples in the literature. However, in surveying such examples we find that these […]

Positive psychology-an introduction

A science of positive subjective experience, positive individual traits, and positive institutions promises to improve quality of life and prevent the pathologies that arise when life is barren and meaningless. The exclusive focus on pathology that has dominated so much of our discipline results in a model of the human being lacking the positive features […]

Behaviour of horses in a judgment bias test associated with positive or negative reinforcement

Moods can influence our judgment of ambiguous stimuli as positive or negative. Measuring judgment bias in animals is a promising method to objectively assess their emotional states. Our study aimed to develop a cognitive bias test in horses, in order to assess the effect of training using positive reinforcement (PR) or negative reinforcement (NR) on […]

Grooming, social rank and ‘optimism’ in tufted capuchin monkeys: a study of judgement bias

Studying the emotional consequences of social behaviour in nonverbal animals require methods to access their emotional state. One such method is provided by cognitive bias tests. We applied a judgement bias test to tufted capuchin monkeys, Sapajus sp., to evaluate (1) whether receiving grooming was associated with a short-term increase in ‘optimism’ (that is, a […]

Bottlenose dolphins engaging in more social affiliative behaviour judge ambiguous cues more optimistically

Cognitive bias tests measure variation in emotional appraisal and are validated methods to assess animals’ affective states. However, the link between social behaviours and cognitive bias has not yet been investigated. Bottlenose dolphins are a gregarious species for whom welfare research is increasing in importance, and thus are a good model to test such an […]