Accounting for individual differences in anxiety, depression or resilience is crucial to ensuring individualised well-being. Personality is reflected by differences in the tendency to approach rewards and avoid threats, and helps to understand what animals, including humans, want and like. At the neural level these tendencies are the result of differential involvement of the behavioural activation system (BAS) and the behavioural inhibition system (BIS). While humans can be classified along BIS/BAS scales through self-reports, such scales have never been validated in non-human animals. In this study we developed the BIBAGO, an innovative test to investigate individual reactions to rewards (BAS) and approach-avoidance conflicts (BIS), by simultaneously presenting a clear positive (treat ball) and a clear negative (waving a plastic bag for 3 seconds) stimuli in a novel arena (2.3 x 2.3 x 1 m), using the domestic pig (Sus scrofa) as a model. We assumed that the duration of interrupting the vocalisations (suggesting heightened attention in individual test settings in pigs) reflects BIS-related behaviours, whereas the occurrence and duration of touching the treat ball and eating the rewards would reflect BAS activation. We also submitted the subjects to four personality tests (Open Field, Novel Object, Human Approach and Novel Peer Tests). After testing 101 piglets, we showed that the BIBAGO is highly repeatable (dICC=0.355 +/-0.058, N=80 piglets) and reproducible (repeatability in an independent sample: dICC=0.433 +/-0.097, N=21 piglets). Using a graphical network approach combined with an extended exploratory factor analysis, we extracted two factors related to BIS and BAS (MSA=0.64, Bartlett’s test ²=602.768, 361 df=171, p<0.001), which are associated with classic personality dimensions. Specifically, exploration of a novel human (loading: 0.323), novel object (loading: 0.457) and novel arena (loading: 0.319) loaded on the BIS-related factor. This is in accordance with the idea that BIS is activated in novel and uncertain situations. Interestingly, we demonstrate that novelty elicits individual reactions that are independent of reward responsiveness (BAS). Thus, our study addresses individual differences in perceived reward, an aspect that has been n
