WHY YOU NEED TO UNDERSTAND FEEDBACK LOOPS

There are a few concepts that are so useful, so insightful, and so practical that understanding them empowers you to think through problems and navigate your life. Feedback loops are one of those concepts.

Feedback loops are everywhere.

Our health is maintained by feedback loops. How we eat, sleep and exercise affects not just how we feel in this moment, but how we will feel in the future. Homeostasis is basically a big word meaning “feedback loop for your body.” We can simplify and understand most health problems by thinking of them as broken feedback loops.

Our natural environment is filled with feedback loops. The ripening of fruit trees, predator/prey relationships, locust swarms and desertification are all natural processes tied to feedback loops.

Our societies utilize feedback loops to influence our behavior. The rise of memes and popular fashions, the way we speak with coworkers, and the way our political parties counterbalance each other are all examples of feedback loops in action. The free market can be viewed as a feedback loop that maintains supply and demand.

And, of course, the coronavirus we are battling today spreads due to a powerful feedback loop (asymptomatic transmission) that takes advantage of our social behaviors. The pain and shock to our economy and daily lives corresponds with how much our daily feedback loops are being disrupted.

HOW FEEDBACK LOOPS WORK (AND WHY IT MATTERS)

Feedback loops are important to understand because they allow us to understand systems and what makes them work. If we can isolate why a system isn’t working, we can fix it. If we can isolate what it takes to get a system working better, we can improve it.

This is true for our health, our relationships, our careers, and pursuing our dreams.

Understanding feedback loops helps you to unlock solutions. They also give you insight into:

• why a small change can lead to a big result

• why consistency often determines your outcomes

• why improvement often seems gradual but occasionally happens rapidly

• why some problems escalate quickly and others resolve themselves

• why interventions are sometimes needed, and

• which types of situations are worth putting more energy into, and which you can “set and forget”

These are big, important ideas. The people who get them right get ahead.

So let’s break down how they work.

The typical image of a feedback loop is arrows going around in a circle. Here are two images of feedback loops using sleep as the example:

The left diagram shows someone who alternates between getting enough sleep and not getting enough sleep. When they sleep enough, they feel energetic and perform better. When they get less sleep they feel tired and perform worse. This person’s sleep pattern keeps them somewhat balanced.

The right diagram shows someone who consistently doesn’t sleep enough. With each successive day, they feel worse, make worse decisions, and their health and performance decline. The longer it goes, the worse it will get.

In both examples, our actions at one step of the process affect the next step, which affects the next, and so on. What makes it a loop is that we continue to come back to the starting point and repeat the process.

We could make diagrams like these for all of the feedback loops we listed above. Let’s not, though. I find this view to be unproductive. I’d like to propose an alternative.

A BETTER WAY TO UNDERSTAND FEEDBACK LOOPS

The key insight is that feedback loops are just a process that repeats indefinitely. When we think of it this way, we can isolate the process from what goes into it and what comes out of it.

I first saw this diagram in an article by Michael Simmons. I love how it isolates the feedback from the process.

Every system has three components: inputs, a process, and outputs. If the outputs can “feed back” into the process, then you have a feedback loop. If the process simply ends, it’s…not a feedback loop.

One of my students put it well: baking a cake is a process. Learning from the experience to improve the next cake is a feedback loop.

When we get enough sleep, our output and feedback are better. When we don’t get enough sleep, our output is worse. If our input and process involve consistently not getting enough sleep, the output and feedback will get worse with every cycle. When we alternate, we maintain balance. When we don’t, our lack of sleep compounds on itself and can send us into a spiral.

Why does the feedback loop lead to balance in one case and chaos in the next?

That’s because they are in fact two different kinds of feedback loops.

BALANCING FEEDBACK LOOPS

Formally known as negative feedback loops, these are processes in which the feedback drives the system to equilibrium. There are “controls” or “thresholds” in place that push the system back toward balance. For this reason, I often refer to them as “balancing feedback loops.”

Over a long time period, the output of a balancing feedback loop looks like this:

No matter where you start, the system pushes you toward the middle. It may or may not actually be at equilibrium, but it will hover inside a normal range.

The classic example of a balancing feedback loop is our body temperature. If our body gets hotter than 98.6 degrees Fahrenheit, mechanisms kick in to cool us off (sweating, etc). If we go below 98.6 degrees, different mechanisms kick in to warm us up (shivering, etc). This system often works so well that every time we measure our temperature it is exactly where it’s supposed to be at 98.6.

When we get too far outside the normal range, we cross a threshold (or “control”). Crossing the threshold triggers a strong response that forces the feedback loop back toward equilibrium.

We already mentioned sweating and shivering. Controls can also be as micro as a disapproving look from your spouse or as macro as the Fed raising or lowering interest rates to keep inflation “balanced” at 2%.

Here are some other examples of balancing feedback loops:

• Bodily systems that maintain homeostasis

• Cruise control in your car

• The water tank in your toilet

• Your home’s thermostat

• Your daily calorie intake

• Your daily sleep routine

• Groupthink

• Risk management

• Parenting teenagers (“Don’t be lazy!” “Don’t be crazy!”)

• Cultural norms

We are at our best when we maintain healthy, balanced routines. These routines can center around our daily lives (eating, cleaning, exercising) or around our projects and ambitions (studying, practicing, writing).

We can manipulate our balancing feedback loops in a couple ways. First, we can decide if our current equilibrium is where it needs to be. If not, we can try to move it up or down. Instead of averaging six hours of sleep every night, we can aim for seven. Instead of running 40 miles per week, we average 50.

Second, we can move the thresholds in or out to allow a wider or narrower range of behavior. Or we can move one threshold and try to hold the other steady. This would be like increasing the quality of our hard workouts, while maintaining the quality of our easier workouts. Or increasing the maximum amount of sleep we get, while maintaining a healthy minimum.

By focusing on the thresholds and the equilibrium, we can tweak our daily routines to get more benefit out of them.

EXPLODING FEEDBACK LOOPS

A negative feedback loop leads to balance. A positive feedback loop leads to explosive growth (or decline). A system with a positive feedback loop may start near equilibrium but it will move farther and farther from it over time.

We are living through multiple exploding feedback loops right now in America. The coronavirus is so effective at making us sick and getting spread to other people that without drastic interventions it will spread through the society too fast for us to handle it. And the repeated injustices felt by the black community at the hands of police has erupted into protests and riots. No single incident caused it. Over time many instances compounded until they hit an inflection point.

But there are other examples with more positive results. I wrote about how learning just 1% per day can lead to explosive gains in knowledge. And earning small percentages on our investments can lead to explosive gains if given enough time. These explosive feedback loops happen everywhere.

Here are a few more examples of positive feedback loops:

• Compound interest

• Cancer cell growth

• Product reviews (and future sales)

• Network effects

• Road rage

• Fads and fashion trends

• Technology adoption

• Spread of ideas

• Spread of disease

• Learning a new subject

• Improving your athletic performance

When the feedback is beneficial, we often call it a virtuous cycle. And that virtuous cycle can be very virtuous. By investing wisely over many years, Warren Buffett turned his fortune into just south of a kajillion dollars.

But imagine a driver in traffic who gets repeatedly cut off or honked at or otherwise treated rudely. If each incident makes his mood a little worse, the repeated incidents can cause the driver to get more and more upset. If it happens enough, his anger might turn into road rage. No specific incident causes it, but the exploding feedback loop can lead him to, well, explode.

There are many areas where we want to create positive feedback loops: saving money, learning a new subject, making a product go viral, and improving our athletic performance all come to mind.

Understanding that these are all positive feedback loops and that we have influence over them is the first step to figuring out how to improve them.

Once we’ve identified a positive feedback loop, there are three keys to improving them.

First, it’s knowing that the real rewards come later. Just because you aren’t seeing them now doesn’t mean your process isn’t working. Exploding feedback loops have long fuses.

Second, a small improvement to a process that is repeated hundreds of times can make a huge difference. But it’s the consistency that matters. Doing one really good workout doesn’t make you excellent. Doing hundreds of really good workouts does.

And third, if an exploding feedback loop looks like it is getting out of control, an intervention needs to be made as soon as possible. An addict who deals with their problem early has a much shorter recovery than one who waits until they’ve hit rock bottom. A product generating negative reviews needs to be fixed or addressed asap.

SUMMING IT UP

The world is filled with feedback loops. By learning how to spot them, we can begin to manipulate them. We can set our balancing feedback loops to an ideal equilibrium, and we can enhance our exploding feedback loops to get us more improvement, faster.