Your Brain and You

In the late 19th Century, Thomas Huxley advanced a view he called “automatism”. This view says that conscious thoughts themselves don’t actually do anything. They are, in Huxley’s famous analogy, like the blowings of a steam whistle on an old locomotive. The steam comes from the same boiler that drives the locomotive’s pistons, and blowings of the whistle are well correlated with the locomotive’s starting to move, but the whistling contributes nothing to the motion. Just so with conscious thoughts: the brain processes that produce our behavior also produce conscious thoughts, but the thoughts themselves don’t produce anything.

Automatism (later known as epiphenomenalism) is currently out of favor among philosophers, many of whom dismiss it without bothering to argue against it. But it has enough legs to be the target of an article by Roy F. Baumeister and colleagues in this year’s Annual Review of Psychology. These authors review a large number of studies that they regard as presenting evidence “supporting a causal role for consciousness” (p. 333). A little more specifically, they are concerned with the causal role of “conscious thought”, which “includes reflection, reasoning, and temporally extended sense of self” (p. 333). The majority of the evidence they present is claimed to be evidence against the “steam whistle” hypothesis that “treats conscious thoughts as wholly effects and not causes” (p. 334).

To understand their argument, we need to know a little more about the contrast between unconscious thought and conscious thought. To this end, suppose that a process occurs in your brain that represents some fact, and enables you to behave in ways that are appropriate to that fact. Suppose that you cannot report – either to others or to yourself in your inner speech – what fact that process represented. That process would be a thought that was unconscious. But if a process occurs in you, and you can say – inwardly or overtly – what fact it is representing, then you have had a conscious thought.

What if I tell you something, or instruct you to do some action or to think about a particular topic? Does that involve conscious thought? Baumeister et al. assume, with plausible reason, that if you were able to understand a whole sentence, then you were conscious, and at least part of your understanding the sentence involved conscious thought. (For example, you could report what you were told, or repeat the gist of the instruction.) They also clearly recognize that understanding what others say to you may, in addition, trigger unconscious processes – processes that you would not be able to report on.

If you want to do a psychological experiment, you have to set up at least two sets of circumstances, so that you can compare the effect of one set with the effect of another. If your interest is in effects of conscious thoughts, you need to have one group of participants who have a certain conscious thought, and another group who are less likely to have had that conscious thought. The way that differences of this kind are created is to vary the instructions given to different groups of participants.

For example, in one of the reviewed studies, participants randomly assigned to one group were given information about costs and features of a cable service, and also instructed to imagine being a cable subscriber. Participants in another group received the same information about costs and features, but no further instruction. A later follow up revealed that a significantly higher proportion of those in the group that received the special instruction had actually become cable subscribers.

In another study, the difference was that one group was asked to form specific “implementation intentions”. These are definite plans to do a certain action on a certain kind of occasion – for example to exercise on a particular day and time, as contrasted with a more general intention to take up exercise, but without thinking of a particular plan for when to do it. The other group received the same information about benefits of the action, but no encouragement to form specific implementation intentions. Significantly more of those who were encouraged to form implementation intentions actually engaged in the activity.

The logic behind these studies is that one group was more likely to have a certain kind of conscious thought than the other (due to the experimenters’ instructions), and it was that group that exhibited behavior that was different from the group that was less likely to have had that conscious thought. The correlation between the difference in conscious thoughts and the difference in subsequent behavior is then taken as evidence for a causal connection between the (earlier) thoughts and the (later) behavior.

There is, however, a problem with this logic. It arises from the fact (which, as noted earlier, the authors of the review article acknowledge) that conscious processing of instructions triggers unconscious processes. We can easily see that this is so, because processing what is said to us requires that we parse the grammar of sentences that we understand. But we cannot report on how we do this; our parsing is an unconscious process. What we know about it comes from decades of careful work by linguists, not from introspection.

Since conscious reception of instructions triggers unconscious processes, it is always possible that behavioral effects of the different instructions are brought about by unconscious processes that are set in motion by hearing those instructions. The hearing (or reading) of instructions is clearly conscious, but what happens after that may or may not be conscious. So, the causal dependence of behavior on instructions does not demonstrate causal dependence of behavior on conscious processes that occur after receiving the instructions, as opposed to unconscious processes that are triggered by (conscious) hearing or reading of instructions.

This point is difficult to appreciate. The reason is that there is something else that sounds very similar, and to which we really are entitled to claim on the basis of the evidence presented in the review article. This claim is the following (where “Jones” can be anybody)

(1) If Jones had not had the conscious thought CT, Jones would not have been as likely to engage in behavior B.

This is different from

(2) Jones’s conscious thought CT caused it to be more likely that Jones engaged in behavior B.

What’s the difference? The first allows something that the second rules out. Namely, the first, but not the second, allows that some unconscious process, UP caused both whatever conscious thoughts occur after receiving instructions, and the subsequent behavior. The experimenter’s giving of the instructions may set off a cascade of unconscious processes, and it may be these that are responsible for both some further conscious (reportable) thoughts and for subsequent actions related to the instructions. If the instructions had not been given, those particular unconscious thoughts would likely not have occurred, and thus the action might not have been produced.

Analogously, if the flash of an exploding firecracker had not occurred (for example, because the fuse was not lit) it would have been very unlikely that there would have been a bang. But that does not show that, in a case where the fuse was lit, the flash causes the bang. Instead, both are caused by the exploding powder.

The procedure of manipulating instructions and then finding correlated differences in behavior thus establishes (1), but not (2). So, this procedure cannot rule out the steam whistle hypothesis regarding conscious thought.

Interestingly, there are some cases for which the authors of the review identify good reasons to think that the steam whistle view is actually the way things work.

For example, one study compared people who imagined a virtuous choice with those who had not done so. In a subsequent hypothetical choice, people in the first group were more self-indulgent than those in the comparison group. This difference was removed if the same activity was imagined as a court-ordered punishment rather than a choice to volunteer.

However, it seems very unlikely that anyone consciously reasoned “I imagined myself making a virtuous choice, therefore I’m entitled to a bit of self-indulgence”. In this, and several similar reported cases, it seems far more likely that the connection between imagining a virtuous choice, feeling good about oneself, and feeling entitled to self-indulgence runs along on processes that do not cause conscious thoughts with relevant content.

The article under discussion is full of interesting effects, and these are presented in a way that is highly accessible. But it does not succeed in overturning an alternative to its authors’ preferred view. According to this alternative view, the causing of behavior (after consciously perceiving one’s situation, or consciously receiving instructions) is done by unconscious processes. This alternative view allows that sometimes, but not always, these unconscious processes also cause some conscious thoughts that we express either in overt verbal behavior, or in sentences about what we are doing that we affirm to ourselves in our inner speech.

[The article under discussion is Roy F. Baumeister, E. J. Masicampo, and Kathleen Vohs, “Do Conscious Thoughts Cause Behavior?”, Annual Review of Psychology 62:331-361 (2011). The difference between (1) and (2) is further explained and discussed in Chapter 4 of Your Brain and You. ]