“We know more than we can tell.”
– Michael Polanyi, The Tacit Dimension

Tacit knowledge is the kind of knowledge that is difficult to convey to another person either verbally, or in writing. It can also be critically important in the process of affecting social change.
Common examples of tacit knowledge include things such as emotional intelligence, or how to speak a language that you’ve learned through immersion over a lifetime, or humor (we all laugh at things that we can’t explain why we find them funny). There are some people who argue (I am not one of them) that leadership itself is a skill that primarily leverages tacit knowledge, gained only from experience.
This intelligence that people often refer to as intuition, is more than a mere hunch. It is the result of subconsciously connecting many bits and pieces of knowledge that we’ve collected over a lifetime. Think about a chess player who makes a rapid succession of moves. Despite the pace of the game, the moves are as calculated as they are situational.
Tacit knowledge is not always correct. It is just as likely as explicit knowledge, to get caught in the trap characterized by that Mark Twain quote, “It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so.” The deep roots of superstition, racism, and all sorts of other human failings lie in the faulty assumptions of tacit knowledge.
Take the so-called “golden rule,” for example: “do unto others as you would have them do unto you.” It doesn’t take training to practice. Its inward orientation suggests that it is based on self-constructed, tacit knowledge. Its biblical origins might even suggest to some that it is some sort of universal truth. The problem is that this “truth” has an inherent bias. The more generous, and effective strategy for human interaction seems to lie in what is known as the Platinum Rule: “Do unto others, as others would have done unto themselves.” In other words, treat people the way they want to be treated, not the way you want to be treated.
Despite its imperfections, tacit knowledge can be crucial to organizing and motivating people to advocate for change. It is expressed in the wisdom of elders. It is the source of the confidence that people place in a community’s opinion leaders, people who have gained the trust of many people, and whose opinion on an issue serves as a sort of seal of approval for like-minded residents.
The transfer of tacit knowledge is so situational, that there is no easy method to measure, or make use of it. This reality is why distributed networks of grassroots activists are more effective than centralized, networks that look like corporate organizational charts.
Capacity inventories and appreciative inquiry interviews, like those that we use in asset-based community development, can go a long way toward uncovering forgotten or hidden assets. It is often, however, easier to discover skills and talents, than it is to discover what people know. Tacit knowledge often reveals itself over the course of the development of personal relationships. Recognizing when uncommon knowledge is being shared is an important skill.