Living organisms, our planet and even the whole universe become more and more complex over time. “Complex” doesn’t just mean “complicated”: it means that the parts of a system interact in ways that give rise to properties that can sometimes be quite surprising.
Each time a certain threshold is crossed, a transition seems to occur in which certain complex systems, such as ants or stars, develop the ability to build other complex systems, such as ant colonies or certain chemical elements.
On Earth, organisms from the animal, plant, and microbe kingdoms can also come together to form complex ecosystems. And we humans build extremely complex social, institutional and technological systems. Thus, complexity can generate more complexity.
Complexity can also develop the ability to manage, control and navigate the complexity it has built. We, for example, manage, control and navigate the complex economic systems and circulation systems we have built. In a sense, complexity can thus “turn in on itself”.
This is one of the reasons why complexity continues to grow. The process is iterative, generating exponentially more complexity over time.
Complexity theorists have described in detail how we act on – that is, to manage or control – complex systems. However, it is less clear how we act in – that is, to navigate – in complex systems. Indeed, it involves making decisions without necessarily controlling the system to achieve the desired result.
For example, we regularly buy groceries in the complex economic system or cross the road in the complex traffic system. We do our best to manage our personal finances with short and long term goals in view, and we plan our daily commutes to minimize traffic time. Regardless of how unpredictable complex systems can be, we generally enjoy good levels of success when taking such actions.
Yet we rarely stop to think about how this is possible.
Rules for Navigating Complexity
There are several ways to answer the question of how successful navigation in complex systems is possible. The “analytical approach” views complex systems as reducible to a single deterministic law or set of laws that allow us to accurately predict their behavior. Presumably, we can then act successfully in complex systems by learning and following these laws.
But most of us have no idea about the laws governing the economy, for example. In fact, if such fundamental laws exist, they are incredibly difficult to discover.
And, there is no guarantee that all relevant complex systems can anyway be reduced to simple laws. Some argue that a system that is reducible was never complex in the first place, just complicated.
Another approach, termed ‘postmodern’, holds that there are no discernible laws for acting in complex systems. The postmodern approach views complex systems as unpredictable and chaotic, which means navigating them involves a kind of existential leap into the unknown – something like a leap of faith. Presumably, successful actions in complex systems are then largely the product of lucky guesses.
The postmodern approach seems to describe some of the decisions we make in the face of complexity. These include those for which there is little evidence and great uncertainty, such as whether marrying a certain person is a good path to a happy life.
However, the postmodern approach ignores most of the actions we perform in complex systems, including buying groceries or crossing the road. The decisions involved in such actions do not ostensibly involve a leap into the unknown. The regularity and reliability with which we perform them suggests that something less arbitrary is going on – something more methodical.
Both the analytical approach and the postmodern approach have problems, but each captures something important nonetheless. Is there a way to get the best of both?
We believe that “reasoning heuristics” – better known as rules of thumb – are at work. In the context of complex systems, rules of thumb follow “emergent” regularities rather than underlying deterministic laws.
An emergent property is a property that is not fundamental, but results from a large number of underlying interactions. For example, individual water molecules cannot ripple, but ripples on a pond can nonetheless emerge from their interactions.
In the same way, complex systems can sometimes be stable and lawful, seen at a certain scale, rather than chaotic, which allows us to make predictions. When the circumstances are right, we can predict what a complex system will do based on its past behavior, and this can inform our current decisions and actions.
This process is of course not foolproof. Sometimes people go to the store to get milk and there is none; sometimes people crossing the road are run over by cars. So there is a sense in which we take a leap of faith, as the postmodern approach suggests. We hope the conditions are right for our rule of thumb to work.
Yet there is also a sense in which rules of thumb are like laws, as the analytical approach suggests: they are, in a sense, methodical and reliable enough to engender consistent success.
Imagine, for example, that you are waiting to cross a road. You see a green pedestrian light, a truck heading for the crosswalk, and various other details. The truck seems to be slowing down, so you deduce that the truck driver sees a red light and is going to stop.
This is how you’ve generally experienced truck drivers in the past (non-psychopathic, sober truck drivers with good brakes). The same goes for the behavior of traffic lights, other pedestrians, etc. So you enter the street.
On the one hand, you obey a rule, even if it follows stabilities in complex systems rather than underlying deterministic laws. On the other hand, you have some freedom to choose one course of action over another.
This happens when a threshold is crossed where complexity develops the ability to apply rules of thumb. The ability to apply rules of thumb could, in turn, amount to the ability to become an agent, something that has an intention and therefore a cognition. Perhaps cognition emerges in the universe when complex systems like living organisms develop the ability to apply rules of thumb to successfully navigate the added complexity they create.