What is the hummingbird effect?

The hummingbird effect refers to the idea that small actions can have a much larger impact or significance. Just as a hummingbird flapping its wings might create a breeze that shifts particles in the atmosphere, leading to major weather changes, our day-to-day actions and choices can end up having very significant repercussions in life, even if we don’t realize it at the time.

Where does the term “hummingbird effect” come from?

The term “hummingbird effect” originated with Edward Lorenz, an American meteorologist and pioneer of chaos theory in the 1960s. He derived it from the concept of the “butterfly effect,” which posits that small causes can have disproportionately large effects. The butterfly effect came from the notion that a butterfly flapping its wings in one part of the world could ultimately cause a tornado elsewhere through a cascading set of changes in atmospheric conditions.

Lorenz adapted this idea in a talk he gave in the 1970s, replacing butterflies with hummingbirds in deference to fellow scientist Ray Bradbury, who did not like the implication that butterflies could cause storms and preferred to associate them with beauty instead. The name “hummingbird effect” stuck as Lorenz and other scientists went on to demonstrate through mathematical models how, in complex systems like the weather, tiny perturbations could create massive changes over time.

The science behind the effect

The hummingbird effect falls under the umbrella of chaos theory and nonlinear dynamics. In classical physics, small inputs were assumed to create small outputs in a linear and predictable fashion. Chaos theory recognized that in complex, dynamic systems like weather, the flapping of a tiny bird’s wings could have an amplified and unpredictable impact over time. This is because in chaotic systems, there are feedback loops that mean effects feed back into and alter causes. The physics concept of “sensitive dependence on initial conditions” also comes into play with the hummingbird effect.

From a mathematical perspective, the flap of a hummingbird’s wing would represent a minuscule change in initial conditions. But in a nonlinear system, that tiny change can cause the system to behave completely differently than if the flap had not occurred. This divergence in behavior arising from infinitesimal differences in starting conditions is what gives rise to the unpredictability and randomness that is characteristic of chaotic systems like the weather, ecosystems, or the stock market.

Examples of the hummingbird effect

While the original metaphor of the hummingbird effect used weather as an illustration, scientists have come to recognize signs of the hummingbird effect all around us, any time a small perturbation has an outsized impact. Some examples include:

• The “butterfly ballot” paper design in Florida which may have swung the 2000 U.S. presidential election to George W. Bush by a tiny number of miscast votes.
• Rosa Parks refusing to give up her seat on a bus in Montgomery, Alabama leading to the year-long Montgomery bus boycott which energized the American civil rights movement.
• The self-immolation of Tunisian street vendor Mohamed Bouazizi in 2010 sparking the Arab Spring protests across the Middle East and North Africa.
• The assassination of Austrian Archduke Franz Ferdinand triggering a sequence of international reactions that led to World War 1.
• The first two cases of COVID-19 spreading globally to cause a worldwide pandemic.

In these examples, as well as many others, small events led to a cascading sequence of increasingly major changes, illustrating sensitivity to initial conditions.

When does the hummingbird effect apply?

For the hummingbird effect to truly take hold, several conditions need to be in place:

1. The system must be nonlinear – In linear systems, small changes create small effects, but in nonlinear systems, effects are not necessarily proportional to causes.
2. There is feedback – A change in one variable needs to be able to influence another variable, creating a feedback loop rather than a straight-line chain.
3. It is a complex system – There are many interacting parts that influence each other. Simple systems with few variables do not display sensitive dependence on initial conditions.
4. The change is small but at just the right place and time – Even in complex systems, a tiny change may not have any effect if the conditions are not amenable to amplification. But a small change timed just right can unleash major differences.

For instance, if Rosa Parks had decided not to give up her seat on a near-empty bus, it likely would not have sparked anything. But doing so on a busy bus full of witnesses turned her small act of defiance into a major catalyst for change in the civil rights movement.

When does the hummingbird effect not apply?

It is important to recognize that the hummingbird effect is not at play in every situation. Just because something has a small impact does not mean it will ripple out in unpredictable and exponential ways. Some key characteristics of situations where the hummingbird effect does not apply:

• The system is stable rather than complex and chaotic – For instance, chemical reactions tend to follow consistent laws of stoichiometry rather than exhibiting sensitive dependence.
• The system is isolated rather than interconnected – Changes cannot reverberate if nothing links components of the system.
• Effects are damped through negative feedback – Many natural systems have negative feedback loops to suppress runaway reactions.
• Society dismisses the change as unimportant – Social systems in particular may need to assign meaning to a small act for it to then gain momentum.
• The change fizzles out quickly rather than self-amplifying – Beyond an initial impact, effects may dissipate rather than compound.

So if a company roles out a minor policy adjustment, it likely will not have dramatic consequences (unless workers decide to mobilize and protest). Many small acts pass unnoticed every day without cascading significance.

Positive and negative examples

Because small actions can lead to such amplified and unintended consequences, the hummingbird effect highlights the importance of being mindful about even minor decisions. There are many positive examples of the hummingbird effect, where small acts of kindness, courage or selflessness ended up having tremendous beneficial impacts by starting a cascade of goodwill:

• A teacher believing in a struggling student who then gains confidence and graduates college.
• Someone breaking up a fight at just the right time to de-escalate larger violence.
• A small donation to an important cause enabling them to gain more support.
• A Facebook post that goes viral and raises awareness of a serious issue.
• A investigative reporter breaking a scandal that leads to significant reforms.

But there are also many worrying negative examples of how tiny sparks can blow up into conflagrations, highlighting why governments aim to surveil and restrict radicalized groups:

• A terrorist attack leading to retaliation and an escalating cycle of violence.
• A rumor gone viral resulting in mass hysteria and panic.
• A misleading tweet by a politician provoking outrage and unrest.
• Small British regulatory changes leading into the Great Irish Famine.
• The assassination of Archduke Franz Ferdinand leading to World War 1.

How can we cultivate positive hummingbird effects?

While the butterfly effect suggests that chaos is inevitable and small changes are futile, the hummingbird effect has a more optimistic implication – that we can have an influence even as tiny individuals. Researchers studying complex systems recommend some ways to increase the chances that our actions have positive, contagious effects:

• Leverage nodes and connectors – Influence people or groups who have existing spheres of influence that can widen the impact.
• Encourage viral ideas and actions – Design memes, hashtags, campaigns to be sticky and contagious.
• Use timing – When the time is ripe, a nudge can set events in motion vs. petering out.
• Embrace diversity – Heterogeneous groups promote cross-pollination of ideas and actions.
• Cultivate collective action – Small acts can turn into norms when people perceive that others support them.

Activists, entrepreneurs, teachers, designers and leaders can all consciously create cascades of positive change starting from their own tiny but well-placed pebbles of initiative.

Conclusion

The hummingbird effect magnifies the impact of small acts of courage, kindness or change by setting in motion ripples that compound and build in nonlinear systems. By recognizing where our actions can lead, we can flap our wings mindfully. Tiny, well-timed interventions in the right conditions can produce tremendous, extended consequences. While the modern world often seems complex and chaotic, the hummingbird effect gives agency back to individuals. Taking responsibility for our own small spheres of influence can shift the world, colibri by colibri.