Complexity: When 1 + 2 Is More Than 3

Unless you’ve been hiding under a rock, you would have heard the word “complexity” being increasingly used in meetings, events and speeches. So what is complexity? Short answer: it’s not the same as “complicated”. Here’s a cheat sheet to get up to speed with complexity, pronto.

When 1 + 2 Is More Than 3

Why do I need to know about complexity?

Governments are increasingly facing “wicked” problems and have realised that solving one could lead to other unforeseen issues. Singapore, for instance, tried to curb an anticipated population boom with family planning policies in the 1970s, but this led to a dependency on foreign workers and a rapidly ageing population. Wicked problems arise as a result of complexity and are hard to solve owing to the multitude of stakeholders, with divergent views and interests. Hence, recognising the complexity of a situation is critical to solving it.

When 1 + 2 Is More Than 3

Complexity in nature

When 1 + 2 Is More Than 3

Nature has plenty of complex systems. An example would be murmuration, when flocks of birds move in a swarm without any one bird being in charge. As they fly, each bird adjusts its location and speed based on the location and speed of those around it. The end result is a range of beautiful, non-uniform yet organised motions that protect the birds by frustrating predators.

Examples of complexity in our lives

Complicated systems


Flying an airplane is complicated — there are many steps — but when done right, the result is predictable.

A car is complicated because it has thousands of parts that interact with one another. But these parts follow a fixed cause-and-effect rule.

Complex systems

air traffic

Air traffic control operations change constantly — with a need to react to weather, aircraft downtime and contingencies, such as a hijacking. The system is now predictable NOT because it produces the same results from the same starting conditions but because it is designed to adapt to changing conditions.


Cars moving on the streets create a complex system as each agent, the car driver, interacts and adjusts his behaviour in response to events that are shaped by human perception, expectations, habit and emotions. Actual traffic flow cannot be predicted with certainty. No driver is in control of the whole system and there is no fixed destination.

When a complex system fails

Complex systems that adjust to disturbances and remain functional are resilient. They fail when a tipping point is reached. Think of a sand pile that collapses, or a human stampede in a mass event.

The greater number of individual elements (or “agents”), and the greater their interdependence and diversity, the more complex is the system.

Scientist are trying to get a handle on complex systems so as to detect “trouble” in the system early on, to prevent a collapse or to bring about fast recovery if the threshold has just been crossed.

This is a new field of interdisciplinary study called Complexity Science. In a nutshell, scientists create models and run simulations on computers that mimic the way individual agents react, interact, self-organise and evolve, with the aim of seeing patterns and tendencies.

Useful Applications

Crowd control

When 1+2 is more than 3

Scientists identified patterns in crowd dynamics that occur immediately before a stampede. Their insights have guided authorities and organisers of large-scale events in their design of public spaces to prevent stampedes from occurring.

Read more about crowd control.

Viral infections

When 1+2 is more than 3

Scientists showed that reducing air traffic drastically would not slow down the spread of certain pathogens. Hence air travel restrictions were not used to deal with the highly infectious Severe Acute Respiratory Syndrome, or SARS.

Read more about viral infections.

Traffic disruptions

When 1+2 is more than 3

Scientists are helping Singapore’s mass rapid transit operators to forecast tipping points that can lead to a cascade of train delays. Their model alerts the operators early so that they can put in place tipping point measures, such as deploying more trains.

Read more about traffic disruptions.

    Jul 7, 2016
    Bridgette See
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