Are lateralized and bold fish optimistic or pessimistic?

• DOI: 10.1007/s10071-024-01876-4
• Publication Date: 2024-06-04T06:01:59Z
• Authors: F. Berlinghieri; G. Rizzuto; L. Kruizinga; B. Riedstra; TGG. Groothuis; C. Brown
• Keywords: Boldness; Pessimism; Judgement; Stimulus (psychology)

Abstract Cognitive bias is defined as the influence of emotions on cognitive processes. The concept judgement has its origins in human psychology but been applied to animals over past 2 decades. In this study we were interested determining if laterality and personality traits, which are known learning style, might also be correlated with a three-spined sticklebacks ( Gasterosteus aculeatus ). We used test go/no-go procedure where fish first trained discriminate between black white card and, after reaching minimum criterion, tested their response an ambiguous (grey). Optimistic subjects expected have high expectation reward associated stimulus, whereas pessimistic non-reward. emergence mirror quantify boldness laterality, respectively. hypothesised that male, bolder more strongly lateralized would optimistic than female, shy less lateralised fish. found males females addition, bold predicted, showed opposite pattern. Finally, colour learned training task faster those card. Our results indicate both traits linked animals’ internal states (pessimistic or outlooks) likely broad implications for understanding animal behaviour particularly welfare context.