Horses Reveal Unexpected Intelligence in Treat Experiment

Horses taking part in a new experiment displayed an unexpected degree of intelligence, seemingly choosing to overlook the rules of a game to gain the greatest number of treats with the smallest possible effort.

"Horses are not natural geniuses," says Carrie Ijichi, an equine scientist at Nottingham Trent University in England. "They are thought of as mediocre, but this study shows they're not average and are in fact more cognitively advanced than we give them credit for."

Only a limited number of studies have examined how horses learn. Some previous work has suggested that they may understand the straightforward consequences of the choices they make.

Horses and forward planning

Wondering whether these large herbivores simply live in the present or possess some sense of future outcomes, Nottingham Trent University ethologist Louise Evans and her colleagues have now shown what many horse enthusiasts may have long believed: horses are capable of planning ahead.

The team tested 20 horses, rewarding them with a treat when they touched a target made from a piece of card.

However, when the target appeared together with a light, no reward was given.

The light was intended to function as a ‘stop’ signal. Yet the horses continued to nudge the target with their noses regardless, collecting their treats when the light was switched off.

Testing the rules of the game

It would be simple to interpret this behaviour as an inability to understand the game. Evans and her team note, however, that there were several other possible explanations for the horses’ actions. They may have understood the rule but lacked the behavioural inhibition to stop, indicating impatience; they may have needed more time than they were given to learn a second signal; or they may have been ‘cleverly’ using a cost-benefit strategy.

To separate these possibilities, the researchers added a cost to the experiment. If a horse touched the card incorrectly while the ‘stop’ light was illuminated, it faced a 10-second time-out during which no reward could be earned.

"We were expecting horses' performance to improve when we introduced the time-out, but were surprised by how immediate and significant the improvement was," says Evans.

"Animals usually need several repetitions of a task to gradually acquire new knowledge, whereas our horses immediately improved when we introduced a cost for errors. This suggests that the horses knew all along what the rules of the game were."

Model-based learning in horses

The researchers think the equine participants initially touched the targets without discrimination because they were still receiving regular rewards without needing to make the effort to judge the meaning of the light. The horses appeared to adopt a cost-benefit approach, ignoring the stop signal until the more substantial penalty was introduced. They then immediately changed their strategy, suggesting a capacity for forward planning once considered beyond them.

The findings show that horses can anticipate future events and modify their behaviour to meet an objective - in this instance, obtaining more treats for less effort.

"We now think that horses may be able to use a form of learning called 'model-based learning' which was thought to be too complex for them. This will now help us to understand their behavior and capabilities much better," explains Ijichi.

"It's fascinating because they have a very underdeveloped prefrontal cortex which is what we typically credit with producing that type of thinking in humans. This means they must be using another area of the brain to achieve a similar result and this teaches us that we shouldn't make assumptions about animal intelligence or sentience based on whether they are 'built' just like us."

This is a mistake humans appear to have made repeatedly with many species, from bees and birds to primates, partly because of misguided efforts to avoid anthropomorphising them.

Yet humanity’s considerable thinking abilities did not simply emerge from nowhere. They have deep roots in our evolutionary past, meaning we are likely to share many cognitive characteristics with numerous other species.

A better understanding of how other animals think can help us build stronger relationships with them and improve the welfare of the other life with which we share the planet.

The research was published in Applied Animal Behaviour Science.