When I came into the kitchen, there was a mess. The bowl of unshelled peanuts on the table had been knocked over and there was a scattering of half-chewed peanut hulls around it.
A trail of peanut dust and debris led to the edge of the table where a chair had obviously been used as an access point. Finally, the most damning evidence: my terrier, Kiko lay curled up in her bed at the foot of the table, surrounded by broken peanut hulls. She had been a naughty girl, jumping up onto the table when everyone was out and stealing peanuts.
'Kiko! You're a bold little dog' I told her sternly. She looked up at me with a guilty expression before slinking off towards the back door, hanging her head.
Most people would mistakenly believe that Kiko knew exactly what she had done wrong. She was mortified at being discovered. Her body language was crying 'I'm sorry! I promise I won't do it again.' In fact, Kiko did not understand that she had done anything wrong and her guilty, meek attitude had nothing at all to do with the peanut incident.
How do I know this? Alexandra Horowitz is a New York professor of psychology who specialises in understanding how dogs think. She observed how dogs behaved when they did something they weren't supposed to do and were scolded by their owners. Then she tricked the owners into believing the dogs had misbehaved when they hadn't. When the humans scolded the dogs, the dogs were just as likely to look guilty, even though they were innocent of any misbehaviour. This simple study proved that dogs don't have an inner sense of right and wrong (like humans). Instead, they have a learned ability to act submissively when an owner gets angry: they have discovered that this is the best way to calm down an angry human being.
We humans are easily fooled: we view our pet dogs like little people, and we naturally presume that their behaviour is done for the same motives as if a human was in their situation. I can promise you that even after being told about this experiment, most owners of dogs like Kiko will continue to believe that their pets are showing genuine remorse for ' bad behaviour'.
It's also very common for owners to believe that their pets understand the English language. Many people have told me that their dog ' knows every word that I say'. Perhaps surprisingly, there could well be significant truth in this belief. Scientists have observed that the average dog can learn 165 words, including signals, and some super-smart individual dogs can learn 250 words. A German Border Collie named Rico knew the labels of over 200 items. He was observed to learn new objects using a method known as 'fast mapping', linking a new word to a new object after only one exposure. Astonishingly, he could remember the meaning of the new word four weeks later, a memory feat that would be beyond many humans.
Dogs are exceptionally talented at observing and interpreting human behaviour, and that means watching us and listening to us. They can't understand complex sentences ('Kiko: if you ever climb up on that table and steal peanuts again, you're going to be in serious trouble') but they have an excellent appreciation of the basics. My daily routine involves taking the dogs out for a walk last thing at night. I just need to say the words 'I'm just going to take the dogs out for a stroll' and Kiko leaps up, dancing around my feet, excited at the prospect. Yet I haven't given her any attention or any deliberate cues: she heard my words, and made the link between my statement and my actions on previous evenings. Behavioural scientists believe that dogs have mental abilities that are close to a two-year-old human child, but they are a different combination of abilities: dogs think like dogs, and humans think like humans.
By carefully observation, dogs are highly skilled at learning about situations that bring them benefits. As well as interpreting human words and actions, they can learn the location of valued items (such as the cupboard containing treats), better routes around their environment (the fastest way to a favourite chair) and how to operate mechanisms that get them what they want (such as latches of doors and the way to work food-releasing toys).
There is still plenty that we don't understand about how dogs think, but scientists are working hard to gain more information. There are academic journals dedicated to the subject (such as 'Animal Cognition'), and many university departments are focussed on learning more.
One of the latest developments has been the use of state-of-the-art brain imaging techniques. Dogs have been trained to lie perfectly still inside MRI machines, wearing ear muffs to protect their hearing inside the noisy machines. Dynamic scans are then carried out to monitor which parts of the brain are activated in specific situations, such as words being spoken or gestures being made by owners.
We have much to learn. How do dogs perceive the world? How much emphasis is given to the senses of sight, smell and hearing? What emotions do they feel? By using technology and careful observation, we are making progress.
Kiko, my bold little friend, we are getting closer to working out exactly what's going on inside your busy little mind.