Abstract: The ability to innovate and the social transmission of innovations have played a central role in human evolution. However, innovation is also crucial for other animals, by allowing them to cope with novel socioecological challenges. Although innovation plays such a central role in animals' lives, we still do not know the conditions required for innovative behaviour to emerge. Here, we focused on interindividual differences in innovation by (1) extensively reviewing existing literature on innovative behaviour in animals and (2) quantitatively testing the different evolutionary hypotheses that have been proposed to explain interindividual variation in innovation propensity during foraging tasks. We ran a series of phylogenetically controlled mixed-effects meta-regression models to determine which hypotheses (if any) are supported by currently available empirical studies. Our analyses show that innovation is more common in individuals that are older and belong to the larger sex, but also in more neophilic and/or explorative individuals. Moreover, these effects change depending on the study setting (i.e. wild versus captive). Our results provide no clear support to the excess of energy or the bad competitor hypotheses and suggest that study setting and interindividual differences in traits related to personality are also important predictors of innovation.

Abstract: We collected data from 248 horses of different breeds, age, sex and use, forming four groups: 74 trotters, 70 gallop horses, 60 horseback archery horses and 44 police horses. All horses were trained and ridden/driven in a regular base. Caretakers or owners who were familiar with the target animals were asked to assess their horses’ temperament. The temperament scores were obtained with the 7-point scale questionnaire according to the Horse Personality Questionnaire which has 25 items and has previously been shown to be reliable for the assessment of personality in horses. It measures six personality components in horses: Dominance, Anxiousness, Excitability, Protection, Sociability and Inquisitiveness.
Component scores were calculated according to Lloyd, A.S., Martin, J.E., Bornett-Gauci, H.L.I., Wilkinson, R.G. (2008) Horse personality: Variation between breeds. Applied Animal Behaviour Science 112. 369–383. The component scores were compared across the four examined groups using the Kruskal–Wallis test. Post hoc multiple comparisons tests were then carried out to explore specific breed differences on each component. The value of alpha was set at 0.05 for all statistical tests.
Groups differed significantly regarding Anxiousness and Excitability, but no significant differences were found regarding Dominance, Protection, Sociability or Inquisitiveness among groups. This finding is in line with the findings of Lloyd et al. (2008) who showed that Anxiousness and Excitability components have the highest level of variation between breeds.In our study, gallop horses had the highest rank regarding Excitability and they differed significantly from police horses which had the lowest rank for this personality component. Interestingly gallop horses had the lowest rank regarding Anxiousness, and trotters got the highest rank in in this component.
According to our results gallop horses are the most extreme in their personality. It is conceivable that being excitable is a more favourable trait for a race horse than for a working police horse. However, it is interesting that trotters are more anxious than gallop horses since they also have a high thoroughbred ancestry. The effect of work and training on these horses needs further surveys.