When learning to recognize something new, how high an object is affects how quickly horses learn.

A study that revealed the importance of height involved teaching eight horses to make the right choice between two options. To succeed, the horses needed to remember visual clues. In this case, horses could associate color with getting some carrot.

Horses were first trained in opening a box with their nose to receive a carrot inside. During the experiment, the horses needed to remember that they could only open one color of box. What scientists from Nottinghamshire, England were testing was whether the height of the boxes made any difference to the horses remembering whether it was the black or white box that opens.

Horses have a better memory for things at ground level.

The research compared how fast horses learned when they were looking at boxes lying on the ground versus boxes placed on a table 70 centimetres (28 inches) above the ground. The researchers considered a horse to have learned which color of box would open once the horse chose 70 percent correctly during four consecutive training sessions.

It turned out that a clue's height did affect how quickly the horses learned to recognize the correct choice. When the boxes were raised above the ground, the horses needed to repeat the task many times before learning to discriminate between the right and wrong answer. In comparison, horses quickly figured out how to pick the right choice when they were looking at boxes on the ground.

Horses took an average of 97 trials to learn from boxes at ground level compared with 163 trials for boxes sitting on a table. When horses worked with the lower boxes, they also made fewer errors overall.

This study's authors note that their results point the way to more successful horse training. Trainers will get better response if they offer horses visual cues on the ground rather than two or three feet in the air.