Z. X. YAN ET AL.
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(cleaning related word or pseudo word). All prime words are
adjectives and target words are verbs. All four experimental
stimuli (moral disgust word, non-moral disgust word, cleaning
related word and pseudo word) are rated by 100 participants for
the degree of familiarity and arouse on a 5-point scale (1 = “not
familiar at all” to 5 = “extremely familiar”, 1 = “not exciting at
all” to 5 = “extremely exciting”). The degree of familiarity was
4.32(4.32 ± 2.09) for moral disgust words, 4.35(4.35 ± 2.35) for
non-moral transgressions words. The degree of arouse was
4.62(4.62 ± 2.39) for moral disgust words, 4.57(4.57 ± 2.45) for
non-moral disgust words. The T-test showed that there was no
significant difference existed between moral disgust word and
non-moral disgust word in the degree of familiarity and arouse
(p > 0.05). The level of design is 2 (moral disgust word VS
non-moral disgust but negative word) × 2 (cleaning related
word VS pseudo word).
Procedure
The procedure was the same as experiment 1. Subjects were
seated in a quiet room at approximately 120 cm from a com-
puter Screen. In order to familiarize participants with the task,
experiment started with 14 practice trails (cleaning related word
or non-cleaning related word). Each trial was initiated by a 500
ms presentation of a small white cross on the black computer
screen, followed by a blank screen for 800 - 1000 ms. Then, the
presentation of prime words followed by the presentation of
target words (presentation time for prime was 150 ms, and for
target was 500 ms). The inter stimulus interval (ISI) between
prime and target was 100 ms. Half subject were instructed to
press the “Z” key on the key board (as accurately and quickly
as possible) if the targets were words and to press the “/” key if
the targets were pseudo words. If the participants made an in-
correct response, the computer will emit a 500-ms beep. For the
remaining subjects the response pattern was reversed.
Results
Reaction time is analyzed by two-way repeated measures
analysis of variance (ANOVA). Trials with reaction times be-
low 300 ms or above 1200 ms are defined as outliers and re-
moved from the data set. The results showed a significant prime
word by target word interaction effect [F(1, 38) = 5.01, p < .05]
(see Figure 2). The simple effect analysis indicated that the
reaction time was faster in moral disgust word priming condi-
tion compared to non-moral disgust word priming condition
when the target word was cleaning related word [F(1,38) =
13.30, p < 0.01]. However, there was no significant response
difference between moral disgust word priming condition and
non-moral disgust word priming condition when the target
word was non- cleaning related word [F(1, 38) = 0.54, p >
0.05].
However, the analysis of the accuracy did not show signifi-
cant main effect on prime word [F(1, 38) =0.008, p > .05], tar-
get word [F(1, 38) = 2.91, p > .05], or prime word by target
word interaction effect [F(1, 38) = 0.639, p > .05].
Discussion
As predicted, we also found that subjects made more fast re-
sponse for cleaning related word when primed by moral disgust
word compared to non-moral disgust word. This was likely
because that the exposure to moral disgust word made people
more desire for cleaning, which contributed to faster processing
of cleaning related word compared to that of primed by
non-moral disgust word. This is consistent with previous study
of moral cognition where a threat to the moral self would moti-
Figure 2.
Effects of reaction time and accuracy as a function of prime words
(moral disgust word or non-moral disgust but negative word) and tar-
get words (cleaning related words or pseudo words). Error bars repre-
sent standard error.
vate cleansing activities (Zhong & Liljenquist, 2006). In the
present study, we also proved that the exposure to moral disgust
situation would produce psychological need to engage in clean-
sing behaviors. Moreover, the priming experiment paradigm
made our result more objective and convincing.
General Discussion
There exists a moral-purity metaphor that likens moral
goodness to physical cleanliness (Rozin, Millman, & Nemeroff,
1986; Zhong & Liljenquist, 2006). In the Experiment 1, we
found a stronger connection between moral purity and cleaning.
In the Experiment 2, we further found that the exposure to
moral disgust situation would elicit a psychological need for
cleaning. More importantly, these results were based on the
unconscious level using priming paradigm, which made our
result more objective than that of using other subjective evalua-
tion paradigm. As mentioned in the Introduction, religious ritu-
als or traditional custom might not only be a simple religious or
culture phenomenon, but also an acute reflection of human
psyche in implicit level. When you wash your body, you expect
wash your soul, which can make you feel clean, chaste, self-
restrained, spiritually pure, and should strive to live in a sacred,
divine way, distinguish yourselves from other animals, attempt
to place yourselves close to higher spiritual beings by being
physically and morally pure (Haidt, 2001; Haidt, Koller, &
Dias, 1993). Thus, the psychological meaning of baptism is to
protect the purity of your soul, not just your body.
The implications of this research may be substantial. Future
studies that address the psychological and behavioral conse-
quences of physical cleanliness will provide valuable insight
into regulatory mechanisms that drive ethical decisions. Given
the boost to one’s moral self afforded by physical cleansing,