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If you’re a big fan of the MBTI, you’ve probably heard of cognitive functions. Introverted sensing (The Si function) is just one of 8 cognitive functions.

Cognitive functions are how the various MBTI types collect and absorb data from the world. This article discusses what introverted sensing means and the signs that show someone uses it.

What is Introverted Sensing (The Si Function)

Introverted Sensing, also known as Si, is a pattern of making decisions based on the information gotten from their environment.

This decision is usually subjective and internal. It is based on past experience and what they believe works. The Si function allows users to take information in with their senses and compare their new experiences with previously stored ones.

Once this is done, they can now make appropriate decisions. This process can take a while because they are very intentional about it. Si also allows them to store new experiences and use them when similar situations appear.

As you probably already know, every MBTI type has 4 main cognitive functions (aside from shadow functions). If you use Si, it should be among the first 4 functions. For example, ESFJ uses Si as their auxiliary function while ENTP uses it as their inferior function.

Their position on the cognitive stack shows how comfortable the MBTI type feels using them.

Signs That You Use the Si Function

While all users who use the Si function will experience these signs, it will be more pronounced with users with Si as their dominant or auxiliary function.

Having said that, here are sure signs that you use the Si function.

1.   Routine and More Routine

Si values past experiences. Thus, if a particular pattern has worked in the past, they stick to it. This leads to routines. Their whole day is planned out without even thinking about it.

For example, they might visit the same restaurant regularly for more than a year. Si users are often loyal customers who stick to what they already know.

The fear of the unknown is real and ever-present to them.

2.   Comparing Past and Present

Si users have stored copies of their experiences in their heads. So, when they face a familiar challenge, they refer to those past experiences and the decision that was taken.

These experiences will be more trusted than any scientific or modern innovation. This is especially true with dominant Si users.

3.   Longer Time Needed to Make Decisions

This follows the last point. Because they constantly need to compare and contrast, they hardly make quick decisions.

They dwell on the situation and usually need something more to push them over the line. If it’s a new experience, seeing someone they know take the leap and succeed can help.

4.   Subjective vs Objective

Si users are more subjective in their approach to information. They trust their experiences or the experiences of others more than verifiable information.

If you’re a Si user, you’re likelier to do the things you saw work the first time. It’s a herculean task to make them change a pattern or method that has consistently worked.

5.   Mistakes are Seldom Repeated

Because Si users are preoccupied with past experiences, they hardly make the same mistakes. The memory and details of that mistake are clear and vivid in their heads.

Even if the circumstances change, they are very wary of doing the exact same thing again. It makes them very uncomfortable.

6.   Vivid Memory

This follows the last point. Si users have really detailed and vivid memories. They remember people’s names, the place where it happened, and stuff like that.

These vivid memories allow them to make future decisions based on past dealings. If you’re a Si user, people will usually be shocked by the power of your memory.

7.   Less Open To Taking Risks

Because of their love for past experiences and comparison, taking risks will not appeal to them. Just think about it. Si users focus on the past because they don’t like making mistakes.

This means they prefer to play it safe. Taking risks goes against everything they stand for. Expect these people to stay in one job or find it difficult to relocate.

Taking risks is like taking a step into the unknown. That’s terrifying.

8.   They Value Stability

Si users value stability in their lives. This is attained by following certain norms and traditions. Sticking to what they already know and believe makes them less likely to have their lives in chaos.

Of course, users who have Si in their inferior positions, such as the ENTP, might not prioritize stability. However, Si-doms are suckers for it.

9.   Spotting Inconsistencies

Si users rely a lot on their experiences and patterns. They know exactly how things unfolded and what to expect.

So, if there are any inconsistencies with previous dealings, they’re quick to spot it. They are usually meticulous and detail-oriented.

It’s hard to trick a Si user.

What MBTI Types Use Si?

Cognitive Stack	MBTI Types
Dominant	ISFJ and ISTJ
Auxiliary	ESFJ and ESTJ
Tertiary	INTP and INFP
Inferior	ENTP and ENFP

Eight MBTI types use the Si function. The types can be divided into four categories according to the position on their cognitive stack.

• ISFJ and ISTJ use Si as their dominant or primary function.
• ESFJ and ESTJ use Si as their auxiliary function.
• INTP and INFP use Si as their tertiary function.
• ENTP and ENFP use Si as their inferior function.

The position on their stack determines how much each type relies on the Si function.

Commonly Asked Questions About the Si Function

How Do You Spot a Si User?

Si users are more likely to make decisions based on their past experiences. They are also scared of the unknown.

Someone who has developed a routine of where they eat or where they buy groceries might be a Si user.

What is the Difference Between Si and Se?

Si focuses on subjective thinking and experiences, while Se is more present. Click that link for a detailed explanation of the differences between Si and Se.

Is Si a Perceiving Function?

Yes, Si is a perceiving function. Thus, the level of control the user has over it is reduced. It happens subconsciously and can be difficult to halt.

How Do I Know if I am Si or Se?

You can know this by identifying your MBTI type. You can also look at the differences between Se and Si.