Instinct Vs. Impulse

 This post shall be a short text; being written in response to a question: What is the difference between instinct and impulse? Let’s examine it in more detail.

First, let’s define instinct. An instinct is an innate, typically fixed pattern of behavior in animals that occurs in response to external stimuli. For example, when a dog is wet, it will shake itself instinctively to dry itself off. The tendency is innate and does not occur as a result of environmental learning or conditioning. An instinct should not be mistaken for a reflex however, as, while this is also innate, it is a simple neural response. For example, the rutting reflex occurs in babies when an object is brushed against their cheek. The baby is reflexively searching for a nipple to suckle. In contrast, running when confronted with a bear is instinctual, as the resulting behavioral output is more complex, yet requires no previous learning.

Next, let us define impulse. Simply put, an impulse is a wish or an urge. When someone has the desire to perform an action, this is said to be an impulse. If one acts on this impulse without regard to consequence, they are said to be impulsive. Impulsivity can present as a personality trait when it begins by early adulthood, is relatively stable and occurs in a wide variety of contexts. While rewarded in the right circumstances, it is generally considered a problematic pattern of behavior.

So, while instincts are innate tendencies of behavior, impulses are urges that occur within us. While the impulse to do something can be the result of instinct, as in the bear example, impulse is a desire that results from external stimuli, while instinct is the tendency for a fixed action pattern. While the two constructs overlap, they are distinct in their phenomenology.