What is Intelligence?
Humans are proud of many things, from particle accelerators to poetry to Pokemon. All of them were made possible because of something humans value incredibly: intelligence. We think of intelligence as a trait, like strength or height. But when we try to define it, things get fuzzy.
In a nutshell, intelligence is a mechanism to solve problems. Especially the problem of survival, which includes finding food and shelter. Intelligence is not a single thing. It includes the ability to learn, be creative, form strategies, or think critically. It manifests itself in a variety of behaviours, from instinct to awareness. But not all scientists agree where it begins or what it even is.
Intelligence isn’t exactly clear-cut, so we can think about it as a flexible set of tools. The basic tools in the intelligence toolbox are the ability to gather information, save it, and learn from it. Information about the world is gathered by senses such as vision, smell, sound, touch, or taste. These senses help us react to the external world appropriately. But living things also have to keep track of their own bodies, things like hunger and fatigue. Information is the basis of action for all living things. Without it, you’re at the mercy of your surroundings, unable to react flexibly. Information is much more powerful if we could file it away for later use. So, memory is the second tool.
Memory is the ability to save and recall information. Memories can be about events, places, associations, and also behaviours like hunting or foraging methods. Some of these, like flying, have to be repeated over and over until they’re mastered. This is what we call learning: the process of putting together a sequence of thoughts or actions.
These three tools enable seemingly stupid creatures to act wisely. The acellular slime mold, which is basically just one huge slimy cell, shows behaviour similar to an animal with a simple brain. When put in a simple maze with food at one end, the slime mold explores its surroundings and marks the paths with slime trails. As it continues to explore, it avoids the marked trails. This behaviour is hardwired and scientists can’t agree if this is intelligence, although it gives the slime mold a certain advantage.
Bees are an example of more adaptive intelligent behaviour. Scientists trained a bumblebee to move a coloured ball into a gall post for a sugar reward. Not only were the bees very skillful at this behaviour, but they got more efficient over time. When several balls were available, the bees chose the one closest to the goal, even though it was a different colour than the ball they were trained with.
For more challenging problems, we need more flexibility: fancier tools. Building on the basic tools, more complex animals have a wider range of problems they can solve. They can memorize all kinds of things. We call this tool ‘the library of knowledge.’
Take raccoons. Their favourite food is human food. Their approach to getting hold of this kind of food is a set of theoretical and practical skills. These skills make them master burglars, able to unlock doors and open windows. In a study, raccoons were given boxes with a series of complex locks and bolts. They needed less than 10 tries to figure out how to open each lock. Even when locks were put together in increasingly different combinations, raccoons could figure it out. The next year, the raccoons still remembered how to open the boxes.
The most impressive tool in our toolbox is creativity: a sort of mental duct tape. Being creative means producing something new and valuable from apparently unrelated things. In the context of intelligence, this means making new and unusual connections.
In another raccoon study, scientists showed the animals that by putting pebbles into a water tank, they could raise the water to reach a marshmallow floating at the top. One raccoon came up with a much better solution. It tipped the tub over.
Another facet of creativity is applying a new tool to a task: physical tools. Like primates who use sticks to get termites out of trees. Or octopuses who use coconut shells in a sort of portable armour. Collecting materials for later use is connected to an even more complex level of problem-solving: planning. Planning means considering the activities required for a certain goal and putting them together in a plan. When unforeseen possibilities pop up, they need to be assessed according to whether they match the plan or not. An example of this intelligent behaviour is hoarding food to eat later.
This is an instinctive behavior in squirrels. But even though hiding food comes instinctively to them, they still need to use advanced thinking skills to make the best decisions. Squirrels examine each nut and weigh the time and effort it would take to hide it, against the benefit they would get from each one. Damaged or low-fat nuts are eaten right away, while nuts that still need to ripen go to the stockpile. Squirrels also pretend to bury nuts when they feel watched. Their goal is to distract rivals from the real nuts.
This is pretty advanced strategizing because, to make a plan to distract someone else, you first have to be aware that there are others like you who are looking for the same things as you are. The more complex the problem, the more tools are needed in combination to solve it. But even for complex problems, each animal’s individual situation is what counts.
Squirrels are omnivores that defend their territories fiercely. For them, it makes sense to remember where there’s food in different locations and trick their enemies. Sheep don’t have any tricks up their sleeves but, then again, they don’t need to. They are grazers and live in flocks. The skills relevant to them are social. They recognize and remember many sheep and humans; a completely different skill. Evolving and retaining a complex set of abilities they’ll never use is a complete waste of resources for them.
Humans went the opposite way and invested in an unusually diverse intelligence toolkit. While this was helpful, by accident we added another set of tools on top: culture. No single person could ever build a space rocket. But thanks to our ability to work together, we can overcome challenges beyond any single individual’s ability.
This allowed us to shape the planet to our liking. We also created new problems in the process. To solve these, we’ll have to look past short-term survival and think about the distant future. We have the toolbox; we just need to use it.