Introverted Sensing (Si)

Introverted Sensing or (Si) is one of the 8 cognitive functions according to Carl Jungs theory. It is a Percieving function - meaning that it is used to learn information. This function is dominant for ISTJ and ISFJ personality types, and the auxiliary function for ESTJ and ESFJ personality types. 

In other words, if your Myers Briggs type contains the letters SJ, then you use introverted Sensing as one of your top and strongest mental processes. It is a natural strength for you and the primary way that you take in new information. 

Unlike types who use extraverted sensing, who absorb sensory information in real time from the external environment, introverted Sensing users prefer to collect sensory experiences and impressions over time. Therefore they observe and remember what has worked before and stores this information as memories. 

Introverted Sensing users place high value on tradition, duty and routine. They are able to look into history and learn from past mistakes, and usually prefer to do things the way they have always been done. Si users learn by remembering facts, details and are usually able to follow instructions easily. 

The types that use this function can sometimes seem like walking encyclopedias. They have incredible long term memory access and this makes the amazing at recalling information like details, facts and dates about an experience they had.

Introverted Sensing seeks comfort and security. They do not see the utility in exploring new, innovative ways of doing something - and prefer to stick to tested methods that have worked before. They work best when given clear and detailed step-by-step instructions on how the job is meant to be carried out. Therefore they tend to prefer work that is stable, consistent and doesn't require them to innovate too much. 

With Si, the individual perceives mostly stored memories of previous sensory experiences. So when they do experience something sensory in real time, they quickly compare it to their stored memories of what has happened in the past. 

The perfect example of an Si user would be a quality assurance inspector. Their job is to look at specific items coming off the production line, recalling every detail. Then to inspect and compare new items to the usually accurate image which they have stored in their minds.

They make great inspectors because they can easily detect the smallest nuances or defects in something they have seen before. Introverted Sensor's brains are wired for this. Their teaching style in similar in that they expect their students to follow precise, step-by step systems to get to a specific result. 

Even when they are training someone to exercise, they will have an image in their mind of how and in what order the person should move, lift a weight, move their bodies etc. The Introverted Sensor trainer can then instruct the person to exercise effectively and safely.

What makes Si users so interesting is that the individual's brain is wired to make comparisons. They recall images and sounds so vividly that their memory of something can seem more real than what they are Sensing in the moment. They experience memories as if they're playing a movie over in their heads, which can at times feel more real to them than the present reality. 

Thus people with dominant Si usually have the ability to recall a past experience in great vivid detail, complete with any stored emotions. A dominant Si can re-experience a past event just as if it was happening live, complete with memories of how they were feeling at the time.

The types that have this function in their stack believe in fulfilling their duty and when given a choice - will always choose to do what they “should” do, as opposed to what they want to do. Therefore, they are not always seen as flexible and spontaneous by other types, but their unwavering focus and determination ensures that they are always achieving their goals. 

Personally, in the past I have struggled to understand and appreciate this cognitive function. As an INFJ - I do not use Si in my cognitive function stack. In fact - for me it is in the Demon position of my shadow. My father however, is an ISTJ - and it was through all the turmoil of misunderstandings and conflict between us - than I began to seek answers as to why we had trouble getting along. 

I must say, I gained a lot of compassion by learning about personality typology. By understanding how his mind works and why he makes the decisions he does - our relationship has improved immensely. I can now learn to appreciate his values (although different from mine) and communicate with him in a way that respects his world-view.