Is the bucket half full, or half empty?

Working out the horse’s state of mind is a challenge, but a small step towards understanding it better has been made with our study on optimism and pessimism.We wanted to find out whether there is any correlation between the horse’s laterality (i.e. its preference for one side or the other) and its “cognitive bias”, in other words, its state of mind.We tested this in an indoor arena using a box containing food treats. The box could either be “positive”, meaning the horse could open it and get the treat, or “negative”, meaning is was locked and the horse could not get the treat. For half the horses, the box was positive when it was on the right hand side of the arena, and negative when on the left, and for the other half, it was positive on the left, and negative on the right. When all the horses consistently approached the positive position and not the negative one, we put the box in the middle, in a neutral position. If the horse approached it in expectation of getting a treat, we considered the horse “optimistic”, and if the horse did not approach in expectation of finding it locked, is was considered “pessimistic”.Whilst there was no significant correlation between the horses’s sensory laterality (preference for eye, ear, nostril etc) and its state of mind, we did find that horses that the horses that were optimistic about the box in the middle were more likely to move their right foreleg first when going to approach it.It’s only a first step, but it does open up a fascinating area for further research! You can read the full article below.

Isabell Marr, Kate Farmer, Konstanze Krüger (2018). Animals 8, 219, November 22nd.