What Is Unconditioned Response in Psychology?

Unconditioned response (UR) is one of the earliest concepts coined by Ivan Pavlov, a Russian physiologist, who was perhaps best known for his work in classical conditioning. According to Pavlov, “unconditioned response” refers to an automatic or reflexive response usually elicited by a specific stimulus.

The term unconditioned is used because this response is not influenced by previous experiences and enculturation. It surfaces directly from biological or physical roots without prior learning. This article will clarify what an unconditioned response is, the differences between an unconditioned response and a conditioned response, and more.

What Is an Unconditioned Response?

An unconditioned response is an unlearned reaction to a stimulus. In simpler terms, it is an unlearned reflex* that occurs naturally in response to a particular stimulus.

*A reflex is an innate behavior that reacts to a specific stimulus. It occurs instinctively and automatically, without any conscious thought. A simple example of a reflex is the eye blinking when an object comes too close to the eye.

The unconditioned stimulus may be a sound, light, taste, or touch. The response is usually involuntary and automatic.

For example, when you hear a loud noise, your ears will automatically contract, and your eyes will blink. When you drink something sour, your mouth puckers, and you taste the sourness in the back of your throat. This is an unconditioned response to the sensation of sourness in your mouth.

Unconditioned responses occur without any learning. They have been around since before humans existed on Earth, so they are hardwired into our brains at birth and do not require training to learn them. An unconditioned reflex does not need reinforcement or punishment to work properly because evolution has programmed our bodies to protect us from danger or pain.

Examples of the Unconditioned Response

The unconditioned response is the basic and instinctive reaction to a stimulus. It happens without thought, without effort, and without any conscious desire to respond. A few examples of unconditioned responses include:

  • Salivation (is mouth-watering) when you smell food that you like.
  • You hear a loud sound and cover your ears because it hurts.
  • You see someone yawning, and you yawn too.
  • Crying when a baby is hungry or uncomfortable.
  • Having a panic attack when faced with danger.
  • Feeling the need to sneeze after being exposed to pepper.
  • Touching the skin with something hot will cause a person to jerk away in response immediately. 

Unconditioned Response and Classical Conditioning

The unconditioned response is one of two components of the classical conditioning* theory proposed by Ivan Pavlov. The other component, the unconditioned stimulus, serves as the natural stimulus for eliciting the unconditioned response.

*In classical conditioning, there are two types of stimuli:

  • Conditioned
  • Unconditioned

Conditioned stimuli are neutral stimuli that elicit an emotional or behavioral response by associating them with other stimuli through classical conditioning techniques. Unconditioned stimuli do not need to be learned or associated with other stimuli for us to react automatically. These natural reactions occur because they were programmed into our brains at birth by evolution or by nature itself.

For example, when a person smells food cooking in his home, his stomach might begin to growl. In this case, smelling food cooking is the unconditioned stimulus, and the growling of his stomach is the unconditioned response.

Unconditioned Response in Pavlov’s Experiment

Pavlov’s famous study with dogs is another example of how a stimulus can elicit an unconditioned response. He rang a bell right before he fed his dogs in the experiment. After repeating this action several times, he found that the dogs would begin salivating when they heard the bell, even if no food was present!

He used the unconditioned stimulus of food and the conditioned stimulus of the sound of a bell to demonstrate how he could condition his dogs to associate one with the other. When he would ring a bell before giving them their food, they began to salivate at the sound alone because it had become associated with eating.

Salivating in response to food is an unconditioned response because it naturally occurs when dogs consume food. However, salivating at the sound of a bell is a learned behavior conditioned by repeated exposure and pairing with food. Therefore, conditioned stimuli are initially neutral but become paired with the unconditioned stimulus. In time, they can elicit conditioned responses when they occur independently.

Unconditioned Response in Little Albert Experiment

The Little Albert experiment is a famous psychology experiment conducted by John B. Watson and Rosalie Rayner in the 1920s. The experiment aimed to show that fear can be conditioned in an infant or young child through classical conditioning.

In the experiment, a 9-month-old infant boy named Albert was presented with a white rat. At this time, there was no emotional response from Albert toward the rat. After several presentations of the rat, Watson and Rayner began to strike a steel bar with a hammer every time they presented the rat to Albert while simultaneously making a loud noise. 

After several pairings of these stimuli, Albert began showing fear reactions to the presentation of either stimulus alone (i.e., the rat or loud noise) because he had learned to associate them together as a conditioned stimulus/unconditioned stimulus pair. Not only that, Albert also began showing signs of fear whenever he saw white furry objects like rabbits or even Santa Claus!

This study is one of the first examples of classical conditioning, where an unconditioned stimulus (UCS) is paired with a neutral stimulus (NS) to create an unconditioned response (UCR). The UCS and NS are followed by a conditioned stimulus (CS), which becomes associated with the UCR. The CS can then be presented without the UCS or NS to evoke the same response as before.

Difference Between Conditioned Response and Unconditioned Response

The fundamental difference between conditioned and unconditioned responses is that a conditioned response is learned, and an unconditioned response is innate. This is important because it indicates the difference between learning and instinct.

Another critical distinction between a conditioned and unconditioned response is that a conditioned response becomes weaker as time passes, while an unconditioned response remains strong. Unconditioned responses are also involuntary, whereas learned responses are voluntary.

In the above example, during classical conditioning, a dog learns to associate the sound of a bell with food. The food is an unconditioned stimulus because it produces an automatic response from the dog, who salivates whenever he eats. The bell, which the dog does not automatically respond to at first, becomes a conditioned stimulus after repeatedly paired with food. The resulting salivation in the presence of the bell is a conditioned response.

The point of classical conditioning is to trigger an unconditioned response (UR) with a conditioned stimulus (CS). The unconditioned stimulus, or UCS, is the trigger for the UR.

Unconditioned Response vs. Unconditioned Stimulus: What’s the Connection?

An unconditioned stimulus is an event or object that elicits a reflexive, unlearned response from a subject. In classical conditioning, an unconditioned stimulus is paired with another stimulus that already produces a strong and well-learned response. The new, conditioned stimulus is then able to produce this same response after only one pairing with the unconditioned stimulus.

On the other hand, an unconditioned response is a reflexive bodily reaction that occurs without learning or conditioning. For example, if you are ever bitten by a bee, you will likely experience an immediate sharp pain in your skin (an unconditioned reflex). This reflex has been built into our bodies through evolution over time – it’s not something we have to learn how to do!

Learn More: How Does Unconditioned Stimulus Work?

Final Thoughts

Our sum can be found in the following key points: Unconditioned response is a biological reaction to an unconditioned stimulus that does not follow a particular pattern (i.e., it is not learned). While the specific response may differ from organism to organism, some unconditioned reactions that have been documented include salivation, increased heart rate, and pupil dilation.

Now that we’ve outlined the theory behind classical conditioning in detail, look for practical applications of these concepts. For example, the ideas will help you anticipate and avoid significant challenges to your new venture. Also, look for ways to use this theory to gain insight into other areas of your life. It isn’t hard to see how this foundation can contribute wonderfully to your life in many ways. The only thing holding you back is your imagination.


  • Eelen, P. (2018, July 26). Classical Conditioning: Classical Yet Modern. Psychologica Belgica. Retrieved April 29, 2022, from
  • Beck, H. P., Levinson, S., & Irons, G. (2009). Finding little Albert: A journey to John B. Watson’s Infant Laboratory. American Psychologist, 64(7), 605–614.

Hi, I am Happy. I'm a professional writer and psychology enthusiast. I love to read and write about human behaviors, the mind, mental health-related topics, and more.