Introverted Sensers are the great observers. They love to gather facts and information from the world around them, and squirrel them away in a giant internal database. Constantly watching, constantly observing, they live to see and record things as they happen.
While Extraverted Sensers live in the experience of the moment and then move on, Introverted Sensers gather information as it presents itself, without passing judgement, and store it internally for the rest of their lives. The act of gathering this information creates a sensation in the IS, an image of a sort, that is quite intense to the IS, and generally beyond expression. They don't know what to think of most of their gathered data, and don't naturally understand its relation to themself. If they later apply a decision-making function to the data, the IS might attach value or meaning to it, and therefore make it understandable to the IS as something that is part of their lives, but if the judging function does not succeed in attaching meaning, the IS remains coldly neutral to the sensory impression. They just don't care.
IS types are the most hard-working and dutiful of types. They are perfectly willing to work hard at most tasks, and succeed by sheer effort, combined with the ability to focus closely on the problem at hand. They like structure, and fit well in the corporate world, often achieving very high ranks. They can do almost any kind of job, but prefer careers that make use of their excellent organizational skills and ability to crunch through data to get to the heart of a matter.
Introverted Sensers are very private people, happy to spend the majority of their time in their interior world of rich sensory impressions. They're open to all of the data they can get, but tend to choose traditional modes of living for themselves. They seek long-term partnerships, and can be counted on to be reliable and committed to their relationships, but they are often perceived as a bit aloof, as if they are holding back on what they really think. In reality, the IS isn't holding back anything that's important to them, they just don't have an opinion. The Introverted Senser is understandably reluctant to take on judging the entirety of its internal world of visions, and so through self-preservation, they reserve judgement about a lot of things. When they do make a decision, it is generally a strongly held opinion and they will express it.
Introverted Sensers value family, history, and quiet living. Their homes are structured and often decorated beautifully. Most IS individuals are very hard-working in the home as well as at the office, and like to stay busy. They tend to be fit and health-minded. They stay close to family members and a few friends, but take pleasure in all kinds of social events, and are highly valued by those close to them.