Horses do not exhibit motor bias when their balance is challenged.

The research investigates the belief that horses can show a bias towards the left or right when their balance is tested, and that this bias can be reduced by equal training in both directions. Experimental results suggest that neither ridden nor unridden horses show this bias, indicating that the perception of bias may stem from human factors instead.

Study Overview and Methodology

• The aim of this study was to understand if horses, when ridden and challenged with tasks that required balance, demonstrated a motor bias – a preference for movement towards one side.
• Thirty horses were included in this study, divided into two groups – unridden (15) and ridden (15). All horses were lunged, where they were asked to canter in circles to both the left and right. This action was used to challenge their balance.
• Three tests were conducted during lunging: measuring the time spent in canter, checking if the horse cantered on the correct lead (a lead being the leg that extends furthest in the direction of movement during a canter), and observing whether the horse remained united (a coordinated pattern of movement of the legs).
• A grazing stance test was also conducted. Here, the horse’s preferred forelimb to extend during the act of grazing was noted. This was meant to evaluate the horse’s bias under conditions where balance was not actively challenged.

Findings

• No bias was discovered in either the ridden or unridden groups when their balance was actively challenged during the lunging tests. However, interestingly, ridden horses did show a motor bias in the grazing stance test – a condition where their balance was not challenged.
• A correlation was observed among the responses across all three lunging tests, indicating a consistency in responding to balance challenges. But no correlation was found between the grazing stance test and the lunging tests.

Conclusions

• The findings suggest that horses do not exhibit motor bias when their balance is challenged. As a result, it’s not justifiable to contend that ambidextrous training (training them equally in both directions) influences any inherent bias.
• Since the estimate of motor bias in horses varied according to test conditions, it’s critical to consider the testing environment when making such assessments.
• If ridden horses are truly unbiased, as the study suggests, the common perception amongst riders that horses have a bias might be influenced more by strong human motor bias.