Horses Demonstrate Ability to Count in New Study

by: Christa Lesté-Lasserre
December 06 2009, Article # 15396

It's no circus trick: researchers have shown that horses can count, despite 100 years of belief to the
contrary.

By dropping apples one by one into two buckets, researchers determined that horses almost always
chose the bucket with more apples, if the numbers were low (less than four). The horses chose
randomly between buckets of four and six apples.

These results are consistent with findings for human babies, and indicate a basic ability to count and
a propensity to learn greater sequences, said Claudia Uller, MPhil, PhD, lecturer in the Faculty of
Education at the University of Cambridge, England, and primary author of the study.

She explained the horses could not see through the buckets, so they had to keep track of how many
apples were dropped into each bucket. The buckets were presented to the horses for choice only
after all the apples had been dropped. Artificial apples were used to prevent any effect of odor. Each
of the 56 study horses was tested only once so as to not be influenced by learning.

Horses still consistently chose two apples over one when the single apple was twice the size,
indicating that they prefer greater numbers to greater volume, Uller said.

"Horses are smart," Uller said. "Not only do they have special social skills, but they also have good
memory, and they can count."

Even so, ever since the case of Clever Hans, the general scientific opinion has been that horses
cannot count. Clever Hans, a famous German stallion, made international headlines in the early 1900s
by hoof-tapping responses to mathematical equations with amazing accuracy. Scientists finally
showed that Hans was influenced by inadvertent cues from his human testers.

But Uller said she has never doubted a horse's ability to count. "Even salamanders can do it," she
said. "Of course a horse is intelligent enough to count."