When it comes to self-deception, we humans are experts. We are quite able of convincing ourselves, for example, that we know something when in fact we really don’t. One of my favorite cogsci blogs, Mixing Memory, describes this phenomenon — called the illusion of explanatory depth — in some detail:

The idea behind the illusion of explanatory depth is simply that there are many cases in which we think we know what’s going on, but we don’t.

There are many great examples in cognitive psychology (e.g., psychological essentialism, in which we believe that our concepts have definitions, but when pressed, learn that either they do not have definitions, or we don’t have conscious access to those definitions), but you don’t have to look to scientific research to find them. If you ask 100 people on the street if they know how a toilet’s flushing mechanism works, many, if not most will tell you “Of course I do!” But if you then ask them to explain it, you will quickly find that they really have no idea how a toilet’s flushing mechanism works. This is the illusion of explanatory depth. They know that when they push down on the flusher, the water leaves the bowl, and then fills back up, but they don’t know how this happens, they only think they do.

The researchers cited in this post found that a person’s overconfidence is highest when explaining how things work (such as toilet flushers) as opposed to citing knowledge of facts or stories. The subjects’ overconfidence was also higher for devices with more visible parts than for those with hidden parts.

The author’s ultimate point is that the illusion of explanatory depth can lead us to deal with information overload by relying on the expertise of others; we think we have knowledge but really we just know about the knowledge.

So how might this phenomenon apply to user experience?

• Do users assume they have more knowledge than they do? (Sure, I know how to use Amazon. Hmm…wait a minute…how do I change my default shipping address?)

• How does the user interface impact the force of the illusion? Which kind of interface is likely to seem easier, one with more buttons (more visible parts) — or a bare-boned interface like Google (less visible parts)?

I don’t have any conclusions to offer (I won’t succumb to the illusion, I won’t). I’ll just keep an eye open for other experts out there on the web who can explain it to me, so I can then convince myself that I knew the answer all along.