A guide on Positive Feedback Loop examples!!
Are you looking for examples of positive feedback loops? Or wondering as to how can positive feedback be applicable in real life? If yes, then you have landed in the correct place.
First, let us look at a positive and negative feedback loop? And how does positive feedback differ from negative? Through our open learning initiative, once we know these two types of feedback loops, understanding the examples would get much easier. Then, we’ll dive into the various positive feedback loop examples.
Although, if you want, you can skip this and scroll down directly to the examples given.
Positive Feedback Loops
Positive feedback loops; sounds cool, right? Indeed, it is. But, here, one might confuse the word “positive” for something good. “Positive” means exacerbating changes (either increase or decrease) in the same direction. Thus, positive feedback exacerbates, accelerates, or increases the change.
In simple language, when X produces Y and Y leads to produce more of X. This, in turn, accelerates the effect of X in the same direction.
This is what we call a positive feedback mechanism or loop. Positive feedback involves changes in output which lead to changes in the input in the same direction.
Think of it in terms of a circle. Imagine a circle starting from a point X, which produces another point Y on the same circle.
Now, this Y again produces point X, completing a circle. And the circle goes on. One could also refer to it as snow bowling. This is why we call it a positive feedback loop.
Negative Feedback Loops
Negative feedback loops are fascinating. In contrast to a positive feedback loop, negative feedback mechanisms involve the opposite direction. This is done to maintain homeostasis and bring back stability from inherently unstable systems.
So, when X produces Y and Y lessens the production of X or has the opposite of what X wishes to produce, maintaining homeostasis, then, it is termed a negative feedback loop.
The main difference between negative and positive feedback loops is in maintaining homeostasis. The positive feedback does not maintain homeostasis. At the same time, negative feedback is interested in maintaining it.
Negative Feedback loops reverse the given change. Thus, balancing the system. On the other hand, positive feedback exacerbates the shift in either of the two extremes, far from the equilibrium. Therefore, imbalances the system as per needs.
Examples of Positive Feedback Loop:
1. Child Birth
Out of all the biological processes, the foremost example of positive feedback is childbirth.
During childbirth, when the labor begins, the child is pushed towards uterine walls to come out of the mother’s womb. This push results in the baby’s head touching the bottom part of the uterus, that is, the cervix. Thus, activating the cervix.
The cervix receptor cells then signal to the brain that oxytocin must be released for the child’s birth.
After receiving the message, the nerve cells in the brain release oxytocin hormone from the endocrine system. Then, the posterior pituitary gland comes into play. Thus, the pituitary gland secretes it into the bloodstream to reach its destination.
Upon arrival, oxytocin increases the uterine contractions in the cervix. Resulting in increased pressure on the cervix. This, in turn, causes the release of more oxytocin which further leads to amplified contractions.
The more oxytocin, the more muscular contractions. This positive feedback loop goes on until the baby is finally born.
2. Blood Clotting
In physiology, blood clot as a process is considered a positive feedback mechanism present in the human body.
When one gets injured or ends up getting a wound, the body tissues present in the place of injury get torn. This results in blood flow outside the body called bleeding.
The platelets near the injury site come to the rescue to stop blood loss from the body. For blood clotting, they stick to the injury site trying to block the blood from going outside the body.
The platelets release a chemical called ADP (adino-diphosphate). These chemicals attract even more platelets to come to the rescue and stick to the wound for blood clotting.
Thus, platelets result in chemicals, and chemicals result in more number of platelets. Adding up in, even more amount of the chemical being secreted for completing the mission of blood clotting.
The chain reaction of positive feedback continues till the blood clot is successful.
Positive feedback loops can be seen in milk production in a mother after childbirth.
When the mother produces milk for the baby, we refer to the process as lactation. There’s an increase in the release of prolactin in the body at childbirth, which is necessary for milk production. When the baby breastfeeds, the breasts get stimulated, promoting more prolactin release in the mother’s body—eventuating in even more milk production.
Mother nature’s positive feedback occurs to ensure that more milk is available so that the mother has sufficient milk to feed her baby.
As the baby stops breastfeeding and nursing from the mother, the positive feedback stops. The prolactin level in the body eventually comes down to normal levels of the pre-pregnancy period due to lack of stimulation.
4. Apple Ripening
All the fruits and vegetables ripen off without us even noticing the process. All the unripe apples ripe on an apple tree, and they eventually overripe. Why do they Overripe?
The answer lies in the process of positive feedback. When one apple on the tree ripens with time, it releases ethylene gas.
When the nearby apples on the tree contact this gas, they also ripen. The gas makes these apples ripen. These apples, after ripening, further release more gas. This makes more apples to ripe. Eventually, ripening all the apples on the tree.
This excellent feedback loop is also used in food production, where the apples are ripened artificially and quickly by exposing the apples to manufactured ethylene gas.
5. Menstrual Cycle
Positive feedback loop examples include their application in the field of biology. The follicular phase of the menstrual cycle is positive feedback. In this, ovulation, the release of the eggs from a women’s ovaries, is caused by an increase in the hormone named estrogen.
This upsurge of estrogen in the woman’s body during menstruation results from positive feedback. The luteinizing hormone surge in females also triggers ovulation and helps control the cycle.
6. Neuron Signaling
In the process of nerve signal generation, membrane depolarization is the occurrence of a positive feedback loop.
When the neuron’s membrane potential increases towards zero during an action potential, the sodium channels open their gate, which increases the sodium conductance. The sodium ions flow into the cell.
This further depolarizes the membrane potential of the surrounding area. And the chemical reactions go on down the axon. Thus, generating nerve signals.
7. Gene Regulation
Among all the positive feedback loop examples, one positive feedback comes from the biological engineering arena. Positive feedback of gene regulation indicates the capacity of a gene to improve its products whenever it wishes to.
The behaviors like bi-stability and hysteresis are also related to a positive feedback loop. Some other applications are the creation of designs for oscillators and amplifiers.
8. Work Place
How a positive feedback loop can be transformative when one is addressing a toxic work environment can be easily witnessed in a workplace. It can be a bit more challenging to know the value it brings when it comes to a positive environment.
Studies have shown that professionals who feel a strong sense of purpose in their jobs are happier in their work. Naturally, employees who are comfortable and have a sense of purpose will feel more connected to their company and are more likely to be productive and produce high-quality work.
Thus, the control centers must increase the sense of purpose in the workplace. Leaving behind an example of positive feedback, which in turn increases the business.
9. Behavioral Investing
Herd mentality is a term used in behavioral investing which causes investors to sell when the market is declining and buy when it’s rising. This is one example of the aggregate effects of positive feedback.
In simple words, positive feedback loops are the key reason that market declines lead to further market declines rather than returning to normal levels. And increases often lead to further gains.
To explain in detail, a rise in demand for a particular company’s share causes that company’s share price to rise. This rise could spur investors to buy that company’s share in the hopes that they can profit from the continuation of the increase in prices. This positive feedback further escalates the demand for that company’s share.
When a cycle of positive feedback continues for too long, investor enthusiasm can lead to irrational exuberance, precipitating asset bubbles and eventually leading to a market crash. This highlights the effect of the opposite, negative feedback loop.
10. Melting of Sea Ice
Concerning the environment, an example of positive feedback is the melting of ice, especially sea ice. Scientists know that ice is light-colored and reflective in nature. The ice acts as a barrier between the sea and sunlight. So, when a large amount of the sun hits the ice, it bounces back and doesn’t cause global warming.
But, when the ice melts, the sunlight directly falls on the sea surface and gets absorbed. This, in turn, leads to an increase in warming—also decreasing albedo, the amount of sunlight reflected by the earth’s surface.
Thus, more warming results in the melting of even more sea ice in nature and so on. It can also lead to climate change which could alter the climate system altogether.
11. Habit Formation
According to psychology, the entire theory of rewarding good behavior for habit formation is based on positive feedback loops.
Imagine, one morning, you start meditating. After some meditation, you feel peaceful, calm, and relaxed. You sense gratitude. Now, these are the various rewards that meditation provides.
Once again, the behavior of meditating will cause the reward of calmness. Because of these rewards, the next day, you will feel motivated or will be more willing to contemplate than before. This cycle of behavior and reward will go on and on.
The more you meditate, the more reward you will experience. The more rewards you share, the more you will be motivated to meditate the next time. In this way, the behavior gets repeated several times over some time. Thus, forming a habit.
This is the reason they say, the more times you repeat a habit, the stronger the habit becomes. Although, negative feedback loops could become a barrier in good habit formation.
12. Multiplier Effect
Among all the different examples of positive feedback loops, one in economics is the multiplier effect. In the study of the economy, the multiplier effect refers to a situation where an initial increase in the economy’s circular flow leads to a higher level of growth in the GDP.
For instance, some government investment in the economy leads to more significant job creation and thus increases the country’s GDP to a much greater extent, just like the ripple effect.
12. Social Proof
As per sociology, social proof is a phenomenon of positive feedback loops. When you see a store filled with customers, it makes it seem that the store is worth a visit, even if you weren’t planning to do that initially.
This increases the number of customers inside that store, which increases the chances of people outside the store entering it to shop.
Also, when a lot of people believe in something. That particular belief is often assumed to be the truth. Though, doing this is a logical fallacy. But, it shows how positive feedback loops are relatable in real life.
Examples of Negative Feedback Loops:
#1. Body Temperature Regulation
The way the human body temperature is regulated inside the body is a remarkable example of negative feedback. Imagine you enter an igloo or some cold room. The temperature fluctuation outside is detected by the hypothalamus inside the body.
Increase heat production so that the body temperature can be maintained. Heat production is what prevents the body from freezing. Thus, the body shivers in response.
In contrast, suppose you go to a dessert or are under the sun in a hot climate. The hypothalamus will send the message to the sweat glands through nerve impulses. The sweat glands will produce sweat so that it evaporates. As a result, the body temperature cools down.
Both these biological systems show how the body’s response to the external environment works to bring about a stable internal environment with the help of a negative feedback loop.
#2. Regulation of Blood Pressure
The very core of blood pressure regulation is negative feedback. When blood pressure increases, there’s a nerve response; wherein a message is sent to the brain from the blood vessels. The brain sends signals to the heart.
Reducing the blood pressure, bringing it back to the normal range. As a result, the heart slows down. Thus, the blood vessels are at ease. This is how the process of blood pressure homeostasis works.
On the other side, when blood pressure decreases, blood pressure homeostasis gets back to work. The blood vessels again send the message to the brain. Then, the brain asks the heart to beat fast. This increases blood pressure, and stability is achieved.
#3. Blood Sugar Regulation
The components involved in regulating blood glucose are none other than feedback loops. Firstly, the terms blood sugar and blood glucose are often used interchangeably.
Now, in the case of a low blood sugar level, the blood glucose concentration in the body decreases. To bring back normal function, the pancreas release glucagon, which travels to the liver. Then, it causes glucagon to be broken down into glucose.
This glucose goes into the bloodstream. Thus, the blood glucose levels are brought back to normalcy with the help of negative feedback.
The control centers come to the rescue in instances where the blood glucose concentration increases, causing high blood sugar. The insulin inside sends messages to all the liver and muscles to store the excess glucose from the blood.
Some of it is stored in the form of body fat, and some as glucagon in the muscles and liver, respectively. In this way, the feedback loops play a vital role in controlling blood glucose, with the combined efforts of the control center in the body.
There are many positive feedback loop examples one can find in real life. And that positive feedback loop examples lie not just in the human body and other science-related stuff, but also different categories like business, economics, psychology, and sociology.
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