Strong claims about unconscious processing are unjustified
Recently, there has been widespread focus on studies of unconscious processing that
have come out of the field of “social priming” (Doyen et al., 2012; Yong, 2012; Shanks
et al., 2013). This focus has primarily been on their replicability (Pashler and Wagenmakers,
2012) and attendant claims of statistical and methodological impropriety (Simmons
et al., 2011; Newell and Shanks, 2014). The logic of the claims made has received
less attention. In this commentary I draw attention to certain limitations on the
inferences which can be drawn about participant's awareness from the experimental
methods which are routine in social priming research. Specifically, I ague that (1)
a widely employed definition of unconscious processing, promoted by John Bargh is
incoherent (2) many experiments involve a perspectival sleight of hand taking factors
identified from comparison of average group performance and inappropriately ascribing
them to the reasoning of individual participants.
The claims made for the role of unconscious processes are strong. For example, one
review states “priming studies have consistently demonstrated that the mere exposure
to environmental events is sufficient to directly trigger higher mental processes,
in the absence of any conscious intentions or awareness that they operate” (Huang
and Bargh, 2014, p. 9). The power of unconscious influences is explicitly placed in
opposition to conscious processing “… by logical necessity [priming effects have]
reduced the presumed causal role of intentional, conscious processes in higher mental
processes” (Bargh and Huang, 2009, p. 128). This leads one review to state “some volitional
behavior does not require any conscious awareness at all” (Dijksterhuis and Aarts,
2010, p. 469). Note that the claim is not that unconscious processes are involved
in judgment, nor that priming can influence higher mental processes. Rather it is
far stronger. Unconscious processes produce judgment, priming triggers higher mental
processes, no conscious awareness is required.
I do not wish to question the reality of these priming effects, in that I believe
that most of these studies could be replicated. Nor do I deny the challenge they pose
to our folk psychology of what influences human behavior (which is often dominated
by a simplistic “all acts have deliberate reasons” model). My purpose is merely to
draw attention to a disjuncture between the methods used to assess unconscious processes,
and the claims made for them in terms of their role in producing action.
Problems with defining unconscious by failure to report
John Bargh has influentially defined unconscious processes as those that “do not influence
subjective experience in a way that [he or she] can directly detect, understand, or
report the occurrence or nature of these events” (Bargh, 1992; Bargh and Morsella,
2008; Huang and Bargh, 2014, p. 14). This definition contains a crucial ambiguity.
How general must the inability to detect, understand or report be for a process to
count as unconscious? Some processes, which we might most appropriately call nonconscious
are forever off limits to our introspection (they are “cognitively encapsulated,”
Fodor, 1983). Others may not be detected, understood or reported on just one particular
occasion. Does this make them unconscious? It seems it does according to the definition
promoted by Bargh.
This new definition has been used to support a shift from defining unconscious as
“without awareness of the stimuli” to “without awareness of the influence of the stimuli.”
This creates two problems. The first problem is it defines the “unconscious” as much
by the self-model of the participants as by that of the experimenter. For example,
Custers and Aarts (2005) is cited (e.g., by Huang and Bargh, 2014) as an example of
subliminal priming which attests to the operation of unconscious goals. The check
which was used to ensure that the stimuli really were subliminal was to ask participants
at the end of the experiment if they were influenced by the stimuli (Custers and Aarts,
2005, experiment 1). In other words, unconscious operation is defined by participants
denying they were influenced. Wilson (2002) has written engagingly about the divergence
of our model of our thoughts and feelings from our actual thoughts and feelings. You
don't need to be social psychologist to see that there could be many influences which
would lead to a participant denying the influence of a stimulus on their choice, and
that these might be factors which—while interesting—weaken the claim that this definition
of unconscious allows us to focus on processes which are both a natural kind and truly
unknown to the subjects (they may, for example, be responding to perceived social
pressure to deny the influence of the factors in question).
A highly cited study (Bargh et al., 1996) reported that participants were unconsciously
influenced by primes in a scrambled words task to walk more slowly down a corridor
upon leaving the experiment. The authors reported, consistent with the definition
of unconsciousness that I wish to question, that “no participant believes that the
word has an impact on his or her behavior” (Bargh et al., 1996, experiment 1, p. 237).
Remarkably, no further test of the awareness of the primes was done on the participants.
Instead, a separate 19 participants were tested and funnel debriefed (with half in
the experimental condition, so we can expect 9 or 10 to have experienced the elderly
primes). The basis for claiming that priming was unconscious is that these participants
could not predict what the influence of the primes would be, nor connect them to the
elderly stereotype. Aside from issues of statistical power in this check, it seems
that no participant was ever directly asked if the primes would affect the specific
behavior which was measured. Even if we did ask them, we would have no strong reason
to believe that the answers we got were because participants were, in some strong
sense, ignorant of the influence of the primes on their behavior. Instead, they may
just give answers which fit with common lay beliefs regarding which factors should
and shouldn't influence behavior.
This issue of how awareness should be assessed, and of possible biases on subjective
reports, is a long-standing one
1
. Reviews have highlighted the difficulty of demonstrating with certainty that a participant
is unaware (Eriksen, 1960; Holender, 1986; Simons et al., 2007; Newell and Shanks,
2014). The way you operationally define consciousness is crucial to whether you can
demonstrate perception without it (Reingold and Merikle, 1990; Merikle et al., 2001).
In contrast to Bargh et al. (1996) other studies have used stricter methods, such
as forced choice questions which remove biases to not report (since they are forced
choice) and allow any feelings of awareness (however weak) to inform the choice (see
Hannula et al., 2005 for a fuller discussion). It is against this background that
Bargh's strategy of defining unconsciousness by failure to report should be judged
(Bargh, 1992; Bargh and Morsella, 2008).
The unjustified perspectival shift which makes claims about individual rationality
based on group differences
The second problem introduced by this definition of unconscious concerns how claims
of the importance of factors in individual cognition are made from experiments which
compare differences in group averages. The logic of many of our behavioral experiments
encourages a perspectival shift in which factors which have the major influence on
each individual's choices are rendered invisible, while an experimental factor which
has a minor influence on each individual's choice is highlighted. This is obviously
the intent—the logic of a between subjects design is to pull out the influence of
the experimental factor against a background of individual variability. Using this
method we identify factors which we can show have a causal influence at the level
of group average. It can be a mistake, however, to talk with confidence about the
nature of an individual's choice, rather than the average effect over individuals'
choices. Consider the statement “Unconscious processes have been shown to produce
evaluation and social judgment” (Huang and Bargh, 2014, p. 9). This is simply wrong
if we take “produce” to mean “be solely responsible for.” Unconscious processes do
not produce, e.g., social judgments. The empirical foundation for this claim is experiments
in which social judgment is produced by individuals, who are quite conscious of what
they are doing at a macrolevel- i.e., willingly participating in an experiment. Unconscious
processes are shown to influence cognitions and behaviors, but they do this as part
of the conscious production of these cognitions and behaviors.
If the unconscious nature of these processes is validated at the individual level
by asking participants to report what influenced their choices, but then the unconscious
process itself is attested to by a difference in group means, it is possible that
the experiment identifies a factor which is a minor influence on the choice as a whole.
In other words the manipulation can show a strong statistical effect (and we'd hope
that as professional experimenters the researchers would design a situation where
this was exactly the case), but for a factor which plays a marginal role in each individual's
choice. Say the experimental task is to evaluate a word as good or bad. The word is
rated as good or bad and each individual, for each judgment, may decide in a way that
is consonant with a deliberate and conscious decision making process (i.e., one which
is completely at odds with the one being foregrounded by proponents of automatic processing).
The dependent variable is reaction time, and the effect of the prime is seen in average
differences in reaction time. The influence of the “unconscious” factor may be to
speed or slow them in their judgment, while this judgment itself may take a value
informed by reasons which the participant is fully aware of. Because “unconscious”
effects are manifest this way, it is misleading to talk of the unconscious as “producing”
behavior when the only thing tested are differences in characteristics of behavior.
This is both because the major element of the behavior may not be affected by the
experimental manipulation (e.g., in this case the judgment of the word as good or
bad, rather than the speed of the judgment), and because it isn't automatic that an
“unconscious” group difference implies an “unconscious” individual judgment.
This perspectival sleight of hand obscures the truly multicausal nature of behavior
behind the single controlled cause that is privileged by the experimenter's perspective.
Participants in these experiments are, as described, making deliberate and reasoned
choices. Their failure to report the influence of the experimental factor may result
from an impoverished or incorrect self-model, or it may result merely from the relative
unimportance, at an individual level, of the experimental factor in guiding their
choices. It is not possible, after all, to report all influences on a behavior, even
for a fully informed and rational agent (the “Frame problem,” Dennett, 1978). For
these reasons, it is not valid for the conclusion to be drawn that unconscious processes
produce behavior, to the extent that this excludes the role of conscious processes
in co-producing them. Nor is it valid to infer that unconscious processes significantly
determine overall behavior of any individual at any time, as is often implied.
Evidence of differences due to unconscious processes at the group level do nothing
to confirm the importance of the unconscious processes in affecting the overall response
of each individual. This concern is particularly relevant for studies of unconscious
processing when the criteria used to define what is unconscious are based on asking
individuals to make judgments about the overall importance of factors. To explore
this, consider the tension between experimental effect sizes and wider generalizability.
Larger effect sizes can be in tension with generalisability
It is not the case that simple inspection of effect sizes will necessarily reveal
the significance of an experimental factor in reasoning. Since effect sizes are based
on the amount of variability in a measure, the experimenter typically selects a measure
or situation in which variability in minimized. Effect sizes are maximized by situations
of tight experimental control—these reduce the influence of non-experimental factors,
allowing a purer measure of the experimental manipulation. Note that this means that
effect sizes can be uninformative about the importance of the experimental factor
in less tightly controlled situations. Indeed, there is a sense in which larger effect
size (indicative of tighter experimental control) may actually anti-correlate with
generalizability (which requires effects which are robust across situations). One
response to failures to replications social priming studies has been that they require
some expertise to set up (e.g., Bargh, 2014)—this would seem to be tacit admission
of the fragile generalizability of such effects.
Conclusion: which influences on behavior is it reasonable to expect a perfectly conscious
agent to report?
The Bargh definition assumes that a rational agent with strong access to the causal
mechanisms supporting their decision process could report all factors affecting their
decisions. I wish to question this. It would be bizarre if individual agents had access
to all the causal factors influencing each of their choices. It would be equally bizarre
if they—unaware of the experimenters' interest in a particularly minor factor—were
guaranteed to report it at the exact time they were asked. By shifting the defining
criteria of unconscious factors to be those which are not reported we open ourselves
to the risk that processes which are fully conscious, or potentially conscious, are
being used to make claims about the unconscious. This may not be a problem if the
revisionist definition of unconscious is born in mind at all times when the implications
of these experiments are discussed. Discussion of whether or not this has been the
case, both within the scientific literature and in popular discourse, is beyond the
scope of this commentary.
The impoverished view of consciousness that results from the Bargh definition is supported
by methods which are designed specifically to render conscious deliberation invisible.
It remains to be shown that human reasoning is not dominated by self-aware deliberation
and based on principles of rationality, which although limited and fallible, can be
considered and improved.
Conflict of interest statement
The author declares that the research was conducted in the absence of any commercial
or financial relationships that could be construed as a potential conflict of interest.