There is no question in my mind (whatever that might be) that most of what is happening in our behavior is driven by unconscious decisions (if we can even call them decisions). There is a lot of evidence for that (for an interesting review check out this book or this article). George Lakoff talks about this a lot, too. He is suggesting that to assume that most of our behavior is rationally driven reflects what he calls the 18th century brain – and that is based on wrong assumptions, or rather assumptions that science has proved wrong. In his book, The Political Mind, Lakoff writes:

But what most people are not aware of, and are sometimes shocked to discover, is that most of our thought – an estimated 98 percent – is not conscious.

Somehow that statement peeked my curiosity. “Thought” in philosophy is generally considered conscious – pretty much by definition. So, it seemed a bit odd. Plus how can they determine this percentage anyways? I decided to take a look at the underlying research. The footnote referred to another book. Not exactly what I expected – books aren’t generally peer-reviewed. But, okay, I figured I could see what that book says. Fortunately, the page in the book I needed to take a look at is available online. And guess what! Yes, this book refers to two other books! One of them again had the relevant page available (page 84 as cited in Rock). Phew. And that finally had a reference to an article:

In a review of the scientific evidence pertaining to this question (and related matters), Bargh and Chartrand (1999) concluded that 95% of our actions are unconsciously determined. This way of measuring consciousness therefore suggests that it accounts for only 5% of our behavior.

The article is a fascinating read (a PDF version is here)! But, my source hunting wasn’t done yet as Bargh and Chartrand made yet another reference:

Tice and Baumeister concluded after their series of eight such experiments [on ego depletion] that because even minor acts of self-control, such as making a simple choice, use up this limited self-regulatory resource, such conscious acts of self-regulation can occur only rarely in the course of one’s day. Even as they were defending the importance of the conscious self for guiding behavior, Baumeister et al. (1998, p. 1252; also Baumeister & Sommer, 1997) concluded it plays a causal role only 5% or so of the time.

And what does it say on page 1252 of that article? It’s the first page of the article, which seems a bit odd and then it says this:

Even if it were shown that 95% of behavior consisted of lawful, predictable responses to situational stimuli by automatic processes, psychology could not afford to ignore the remaining 5%.

Even if?!? That’s not how you start a conclusion! That is how you start a hypothetical statement! So, the claim that 5% of our thoughts are conscious/consciousness/controlled by our conscious self is based on a hypothetical statement! I haven’t checked out the sources that aren’t available online (I have requested the books through my library) but this surely does not bode well…

Now, Timothy Wilson writes (on p. 24):

[…] our five senses are taking in more than 11,000,000 pieces of information. Scientists have determined this number by counting the receptor cells each sense organ has and the nerves that go from these cells to the brain […] The most liberal estimate is that people can process consciously about 40 pieces of information per second.

Oh, boy. That references a book… I am not going to track this one down. I don’t know if this will dissolve just like the Lakoff quote. I guess, the lesson learned is to always track back numbers to the original source – you might be surprised as to what you’ll find there!

Where does this leave us? Probably the best conclusion is to say that we really have no clue how much of our activity is conscious and how much isn’t. Well, we actually don’t even really know what consciousness is. It is clear that a lot more happens without our control than we realize – or ever would like to admit. But we probably can’t put an exact number on that. And make sure to check your sources. All the way to the end. Consciously.

A big hat tip goes to Bella DePaulo who has been following claims back to their source for a long time and found all sorts of ones that were not supported by the original research.