Causal explanations affect judgments of the need for psychological treatment

Text-only Preview

Judgment and Decision Making, Vol. 4, No. 1, February 2009, pp. 82–91
Causal explanations affect judgments of the need for psychological
Nancy S. Kim?and Stefanie T. LoSavio
Northeastern University
Knowing what event precipitated a client’s abnormal behaviors makes the client appear more normal than if the event
is not known (Meehl, 1973). Does such knowledge also in?uence judgments of the need for psychological treatment,
and if so, does it matter whether the precipitating event was inside or outside the client’s control? We presented un-
dergraduates with cases of hypothetical clients exhibiting abnormal behaviors and manipulated whether they were also
told of a precipitating event explaining those behaviors. Knowing the precipitant signi?cantly reduced perceptions of
clients’ need for treatment, but only when the precipitating event was outside the client’s control. These ?ndings call
into question the notion that it need always be bene?cial for an outside reasoner to uncover the root cause of a client’s
psychological problems, particularly when the root cause is still unknown to the client. The rationality of the effect and
additional implications for decision-making are discussed.
Keywords: understanding, explanation, clinical judgment, treatment.
1 Introduction
roommate, “Ted,” who has been exhibiting some strange
behaviors. Joe notices that Ted has frequent memory
How do lay people make judgments about another per-
lapses. These lapses lead Ted to repeat his thoughts
son’s need for psychological treatment? Given that re-
to himself, which in turn causes dif?culty interacting
cent estimates suggest that approximately one out of ev-
with others. Worried by Ted’s odd behaviors, Joe is
ery four Americans in any given year have a diagnos-
on the verge of suggesting that Ted seek out profes-
able mental disorder (Kessler, Chiu, Demler, Jin, & Wal-
sional psychological treatment. Suppose, though, that
ters, 2005), it is likely that a great many lay individu-
Joe then hears through the grapevine that Ted’s prob-
als have the opportunity to observe and assess others’
lems all started when his girlfriend cheated on him. Ted
behavioral pathology in their daily lives and to in?u-
was so upset by this event that he started having frequent
ence others’ treatment-seeking decisions. Evidence sug-
memory lapses for his usual daily events (which, in turn,
gests that the treatment-seeking strategies of people suf-
launched his other problems). Will knowing the initial
fering from disorders are strongly in?uenced by lay social
precipitant of Ted’s problems now lead Joe to perceive
networks (Angermeyer, Matschinger, & Riedel-Heller,
Ted as being more or less in need of psychological treat-
2001). Indeed, a prospective client is most likely to ?rst
ment? Or, will Joe treat this new information as irrelevant
decide, with input from peers, whether treatment might
to his judgment of Ted’s need for treatment? The primary
be needed, and to only then make an appointment to talk
question in the current paper is whether, and how, know-
with a mental health clinician. It may therefore be of crit-
ing the initial cause of a person’s abnormal behaviors in-
ical importance to examine factors in?uencing lay judg-
?uences judgments of that person’s need for professional
ments of others’ need for treatment.
psychological treatment.
In particular, we are interested in whether understand-
ing a person’s behaviors in?uences judgments of that
person’s need for treatment. For instance, suppose that
1.1 Meehl’s
“Joe,” a well-adjusted ?rst-year college student, has a
makes it normal” effect
?Nancy S. Kim, Department of Psychology, Northeastern Univer-
sity, and Stefanie T. LoSavio, Department of Psychology, Northeastern
We suggest that some clues to answering this question
University. We thank Woo-kyoung Ahn, Jonathan Baron, John Coley,
may be derived from an informal observation reported by
Joanne Miller, and two anonymous reviewers for helpful feedback. Cor-
Meehl (1973). Meehl noticed that the presence of an ex-
respondence concerning this article should be directed to Nancy S. Kim,
planation appears to in?uence perceptions of the normal-
Department of Psychology, 125 Nightingale Hall, Northeastern Uni-
versity, 360 Huntington Avenue, Boston, Massachusetts 02115–5000,
ity of another person’s behaviors. Speci?cally, he sug-
USA. E-mail: [email protected]
gested that, when people are able to explain an individ-

Judgment and Decision Making, Vol. 4, No. 1, February 2009
Explanations affect treatment judgments
ual’s clearly abnormal behaviors, the behaviors are then
viding information about a precipitating life event (e.g.,
perceived as being more “normal” or acceptable. Meehl
being cheated on by one’s signi?cant other) that caused
termed this general phenomenon the “understanding it
the abnormal behaviors to appear in the ?rst place. That
makes it normal” effect. To illustrate, Meehl described a
is, Ahn et al. (2003) manipulated whether or not the pre-
psychologist testifying as an expert witness at the trial of
cipitating life event was also provided to explain the gen-
a man who murdered his wife. The psychologist argued
esis of the initial symptom in the chain of strange be-
that if he could only ?nd out the entire set of details in the
haviors (e.g., was cheated on ? memory lapses ? re-
case, such as the way the man’s wife talked to him in the
peats thoughts to himself ? dif?culty interacting with
morning, then the homicide would become “dynamically
others). They found that people who knew the precip-
understandable” and the act would thereby become much
itating life event judged the client to be more “normal”
more normal or acceptable. Meehl argued, however, that
than did people who were not told about the precipitat-
any given behavior itself remains at the same level of nor-
ing life event. These results supported the existence of
mality regardless of what explanations another person is
the “understanding it makes it normal” effect. The “un-
able to mentally generate and bestow upon it. In this case,
derstanding it makes it normal” effect speaks to the cur-
according to Meehl, the murder should not be seen as nor-
rent research question insofar as judgments of the need
mal or acceptable, even if we can piece together exactly
for psychological treatment may be strongly (or even al-
what precipitated its occurrence.
most completely) informed by judgments of a person’s
Although Meehl’s paper (1973) did not formally stip-
“normality.” That is, to the extent that a person’s behav-
ulate what constituted understanding, Ahn, Novick, and
iors are deemed abnormal, we might generally expect to
Kim (2003) suggested that people’s intuitive feelings of
judge that person as needing psychological treatment.2
understanding a set of behaviors are strengthened when
they have a coherent explanation of those behaviors, in
1.2 The locus of control of precipitating
keeping with Thagard’s (1989; 1992) model of explana-
tory coherence. Thagard (1992) argued that when an ini-
tial explanatory hypothesis can be explained further by
We also propose that the in?uence of increased under-
an additional explanation, it is perceived to have even
standing on need-for-treatment judgments may be dif-
greater coherence and to provide a better overall under-
ferentially triggered by different types of precipitating
standing of the phenomena than if it had not been fur-
Namely, in previous work, the precipitating
ther explained. (See Read and Marcus-Newhall, 1993,
events all had the characteristic of being outside the per-
for experimental support.) Using our earlier example to
son’s control (e.g., having been abused as a child; Ahn
illustrate, Joe’s initial explanatory hypothesis is that Ted’s
et al., 2003). Previous research, therefore, does not al-
memory lapses cause him to repeat thoughts to himself,
low us to differentiate between precipitating events that
which in turn causes dif?culty interacting with others.
are internally-controlled (performed intentionally by the
Joe’s understanding of Ted’s behaviors is increased when
client) versus those that are externally-controlled (con-
Joe learns that an initial precipitating event (i.e., Ted’s
trolled by outside factors or persons). Both internally-
negative experience with in?delity) caused the chain of
and externally-controlled factors are, however, likely to
odd behaviors to be launched in the ?rst place. That
be generated in real life as explanations for a client’s be-
is, according to Thagard’s (1992) model, Joe’s subjec-
haviors, and there is reason to believe that they could have
tive feeling of understanding Ted’s behaviors should be
markedly different effects on need-for-treatment judg-
stronger than if Joe had not known about the in?delity.
On the basis of this underlying logic, Ahn et al. (2003)
One hypothesis is that people will judge clients to be
conducted the ?rst systematic tests of the “understand-
less in need of psychological treatment when externally-
ing it makes it normal” effect. In their studies, people
controlled events are provided as the cause of their be-
read about hypothetical clients,1 each exhibiting clearly
haviors, relative to when internally-controlled precipitat-
abnormal behaviors. The relationships between the be-
ing events are provided or when no precipitating events
haviors of each client were explained by specifying clear
are provided. People might believe that an externally-
causal connections among them, as in our example of
controlled event, as opposed to an internally-controlled
Ted. The coherence of that explanation was then manip-
one, could happen at random to anyone and that the en-
ulated between subjects by either providing or not pro-
suing symptoms are therefore more understandable (e.g.,
“if that happened to me, I might have problems too”).
1For clarity, we use the term “clients” to refer to hypothetical people
Furthermore, previous decision-making studies in the
showing clearly abnormal behaviors. However, note that in the cur-
rent study, participants always learned about “individuals” rather than
legal domain have found that if crimes are explained
“clients.” Thus, they were not in?uenced by terminology to respond in
any particular way.
2We return to this issue in the Discussion section.

Judgment and Decision Making, Vol. 4, No. 1, February 2009
Explanations affect treatment judgments
by externally-controlled events, such as being from a
therefore translate to recommending less treatment.
low socio-economic status group, more lenient punish-
In summary, our primary objective was to test whether
ments are issued than if they are instead explained by
increased understanding of a client’s bizarre behaviors in-
internally-controlled events (Grasmick & McGill, 1994;
?uences judgments of that client’s need for psychologi-
Monterosso, Royzman, & Schwartz, 2005). To the extent
cal treatment. Our secondary objective was to examine
that both punishments and treatments are seen as inter-
whether the effect is dependent on the locus of control
ventions for abnormal behaviors, this tendency may also
inherent in the explanatory precipitating events (whether
apply to the area of clinical judgment. That is, simi-
they were within or outside the clients’ control).
larly, if a client’s behaviors are attributed to externally-
controlled factors, the client might appear less in need
of psychological treatment than if the behaviors are at-
2 Method
tributed to internally-controlled factors.3
An alternative hypothesis is that internally-controlled
2.1 Participants
precipitating events might be taken to indicate that a
A total of 128 undergraduate students participated (72 in
client is less in need of psychological treatment (rela-
the main study, 12 in each of two different pilot studies to
tive to judgments about clients with externally-controlled
pretest the stimulus materials, and 32 in a follow-up ma-
events or no event). In particular, observers may con-
nipulation check). Participants were given either partial
clude that clients should be responsible for overcom-
introductory psychology credit or $5.
ing their issues if they are responsible for causing them
in the ?rst place.
For example, recent studies have
shown that clinicians feel clients are more responsi-
2.2 Materials
ble for psychologically-caused symptoms (e.g., caused
We ?rst created 22 matched pairs of precipitating life
by personality) than biologically-caused symptoms (e.g.,
events. (The full set of vignettes and corresponding pre-
caused by changes in serotonin neurotransmitter activ-
cipitating events used in the main study is listed in Table
ity; Miresco & Kirmayer, 2006).
This ?nding may
1.) These were designed such that one member of each
be relevant to the current case to the extent that the
pair was an event that was internally-controlled in nature;
“psychologically-caused” symptoms in their study were
that is, it was described as having been carried out by
perceived as more under the internal control of the client
the hypothetical client with intent. The other member of
than the “biologically-caused” symptoms.
the pair was externally-controlled in nature. Members of
psychologically-caused symptoms such as personality
matched pairs were written to be as similar as possible
are not necessarily truly internally-controlled per se, lay
except for this critical contrast. Pairs were approximately
people may nonetheless perceive them as relatively more
matched for length.
internally-controlled than a client’s biological makeup.
Pilot 1.
To check that our intuitions about the
Thus, overcoming symptoms caused by relatively more
internally/externally-controlled nature of these pairs were
internally-controlled factors might be perceived as the re-
shared more generally, we asked 12 undergraduates to
sponsibility of the client, and the client may therefore
rate their impressions of who or what is responsible for
be seen as less in need of professional intervention. Al-
each event. Ratings were made on a scale of 1–9, where 1
though Miresco and Kirmayer’s (2006) study is clearly
= “the individual is completely responsible,” 9 = “people
an imperfect analogy to the comparison of internally-
or circumstances outside the individual are completely
controlled versus externally-controlled causes performed
responsible,” and 5 = “the individual and people or cir-
in the current study, it is nonetheless suggestive of the
cumstances outside the individual are equally responsi-
notion that relatively more internally-controlled causes
ble.” Each person provided ratings for one of two pack-
may reduce perceptions of the need for treatment. Fur-
ets. Each packet contained equal numbers of internally-
thermore, it is possible that withholding treatment, as
and externally-controlled events, but no two members of
opposed to giving it, could be perceived as a form of
the same matched pair. The order of events in each packet
“punishment” for the client who has acted with inter-
was randomized. From the pilot participants’ ratings for
nal control and intent. Being more punitive for behav-
the 22 matched pairs, we selected 12 matched pairs for
iors launched by internally-controlled events, as opposed
which ratings were signi?cantly different from one an-
to those launched by externally-controlled events, might
other (all p’s < .01), and for which ratings for externally-
3One might argue that this may in fact be rational in some cases,
controlled events were greater than the midpoint of 5 and
insofar as treatment might help a client with internally-precipitated be-
ratings for internally-controlled events were less than the
haviors to identify and control the precipitant. On the other hand, it is
midpoint (all p’s < .05; internally-controlled: M = 2.57,
important to note that treatment should still probably be useful in both
cases to help the clients themselves to discover the precipitant and ad-
range 1.67–3.33; externally-controlled: M = 7.79, range
dress the resulting symptoms.

Judgment and Decision Making, Vol. 4, No. 1, February 2009
Explanations affect treatment judgments
Table 1: Study stimuli: Case vignettes and precipitating events (continued on next page).
A. Plausible Vignettes
Case Vignette
Precipitating Event
Precipitating Event
Ever since he enlisted
Ever since he was
Fred has had frequent visual hallucinations that are frightening
in the army. . .
drafted into the
in nature. This causes him to experience unexpected episodes
army. . .
of chest pain and shortness of breath. These episodes, in turn,
cause him to pretend that he has a medical illness to hide the
real cause of his problems.
Because she joined an
Because she was
Leah believes that her thoughts are being listened to by oth-
extreme religious
raised in an extreme
ers. This belief has caused her to give up the social activities in
organization. . .
which she was previously engaged in favor of drinking alcohol
organization. . .
by herself. This, in turn, causes her to be consistently irrespon-
sible about meeting her obligations.
Because he worked
Because he grew up in
Leonard has a strong belief that he is entitled to the good things
hard to become
a wealthy family in
in life. This belief causes him to be unable to resist his im-
wealthy despite being
which he was given
pulses to steal the things to which he feels entitled. This, in
born to a poor
everything he asked
turn, causes him to frequently lie in order to hide his behavior
family. . .
for. . .
from his family and friends.
Because she cheated
Because her husband
Leslie has lapses in her day-to-day memory that interfere with
on her husband. . .
cheated on her. . .
her daily activities. This problem causes her to repeat thoughts
to herself over and over to remember them better. This, in turn,
causes her to have a hard time interacting socially with others.
Because she had an
Because she had a
Sarah frequently suffers from insomnia and is in a habitual state
abortion. . .
miscarriage. . .
of sleep deprivation. This deprivation causes her to have trou-
ble remembering the names of objects. This memory problem,
in turn, leads her to suffer from episodes of extreme anxiety,
because she fears that it will cause her to embarrass herself in
front of others.
Pilot 2. From these 12 matched pairs, we chose 10
which people read the vignettes with no precipitating
that best ?t with the 10 case study vignettes adapted from
events. However, the control vignettes were unavoid-
Ahn et al. (2003). Each vignette contained three abnor-
ably shorter than the precipitating-event vignettes, which
mal behaviors based on symptoms taken from three dif-
might have affected judgments insofar as longer explana-
ferent classes of DSM-IV-TR (APA, 2000) mental disor-
tions may be perceived as more expert-like than shorter
ders, to minimize the in?uence of prior knowledge. The
explanations (Kikas, 2003). Thus, we built in a second
vignette included a description of a causal structure of
“control” by pre-designing ?ve of the vignettes to be im-
the form Symptom A causes Symptom B which in turn
plausible in nature; that is, the overall causal structure
causes Symptom C. The precipitating event condition also
provided was not believable. The other ?ve were de-
included the relation Precipitating Event X causes Symp-
signed to be plausible.4 Because the in?uence of implau-
tom A. In this way, the precipitating event could easily
sible background knowledge on reasoning is known to be
be presented as the root cause of the entire set of symp-
greatly diminished or absent relative to the in?uence of
toms (to produce greater understanding in accord with
plausible knowledge (Ahn et al., 2000; Ahn et al., 2003),
Thagard’s model of explanatory coherence, as discussed
the implausible vignettes should act as control vignettes
that were equated with the plausible vignettes for length.
4To ensure that our plausibility manipulation was successful, we
2.3 Procedure
asked another 12 participants to rate the plausibility of each complete
vignette (on a scale of 1–10, where 1 = very implausible and 10 =
very plausible). As desired, plausibility ratings signi?cantly differed
We designed the study to include two different controls.
between the Plausible (M = 6.74; SE = 0.28) and Implausible (M =
First, we used a between-subjects control condition in
4.51; SE = 0.36) conditions (p < .001).

Judgment and Decision Making, Vol. 4, No. 1, February 2009
Explanations affect treatment judgments
B. Implausible Vignettes
Case Vignette
Precipitating Event
Precipitating Event
Because she keeps
Because her
Dorothy is unable to concentrate on her tasks for any length of
violating restraining
ex-husband keeps
time. This inability causes her to believe that she is being
orders to stay away
violating restraining
distracted by others placing thoughts into her head. This belief,
from her
orders to stay away
in turn, has caused her to be unable to discard worthless
ex-husband. . .
from her. . .
objects, as a way of trying to maintain some control over her
Because she used to
Because she blacked
Erin is frightened of needles and of medical procedures dealing
drink to the point of
out after someone
with blood that could also make her unconscious. This fear has
blacking out. . .
slipped something
caused her to have a constant fear of developing a terminal
into her drink. . .
illness that will require her to undergo medical procedures
involving the use of needles to draw blood. This illness fear, in
turn, has caused her to have recurrent thoughts of suicide,
because if she kills herself she will no longer have this fear.
Because he contracted
Because he contracted
Jason releases his anger by being physically cruel towards
HIV after using an
HIV from his mother
animals. This behavior gives him a sense of power which
infected needle to take
as a baby. . .
causes him to have a greatly elevated mood. This mood, in
heroin. . .
turn, causes him to believe that complete strangers are in love
with him, because happy people are well-loved.
Because he bullied his
Because he was
Jarrod always chooses solitary activities. This causes him to
classmates when he
bullied by his
require excessive attention to make up for the lack of human
was young. . .
classmates when he
contact. This need, in turn, causes him to be unable to
was young. . .
remember new information, because he relies on the attention
of others to remember all the important information for him.
Because she has
Because she was
Pam has become unable to produce facial expressions. This
abused her children. . .
abused by her
de?cit causes her to frequently pull out her hair in an effort to
father. . .
induce enough pain that it will show up in her face. This, in
turn, causes her to uncontrollably shout out inappropriate
words at random times because of the pain.
Equal numbers of participants were randomly assigned
After reading these examples, participants were told
to view all ten vignettes (?ve plausible, ?ve implausi-
to turn the page to begin reading the ?rst vignette. For
ble) in exactly one of the three precipitating event condi-
each vignette, participants were asked, “To what degree
tions (Externally-controlled event, Internally-controlled
does this person require professional psychological treat-
event, or No event). The order of vignette presentation
ment?” Ratings were made on a scale of 1–9, where 1
was randomized for each participant to minimize any in-
= “the individual does not require treatment” and 9 =
?uences of contamination across vignettes. Participants
“the individual greatly requires treatment.” Participants
were asked to read the vignettes, each describing “char-
were instructed to give ratings based on their ?rst impres-
acteristics of a person.” Before seeing the vignettes and
sion of each vignette. They were told that there were no
making their own judgments, participants were given a
right or wrong answers per se and that the experimenters
number of examples for clari?cation. Speci?cally, they
were simply interested in their judgments about the need
were given two examples of individuals, one male and
for professional psychological treatment. They were told
one female, who do not require treatment (e.g., “Andrea,”
in advance that they would not be able to go back and
who worries about her children’s safety, cleans the house
change responses to earlier vignettes.
once a week, and is not completely satis?ed with her
appearance) and two examples of individuals, one male
and one female, who do require professional treatment
2.3.1 Follow-up manipulation check
(e.g., “Mark,” who cries every day, washes his hands ev-
Follow-up ratings were also obtained to ensure that any
ery hour, and wrongly believes his arm is misshapen).
signi?cant differences between the Internally-controlled

Judgment and Decision Making, Vol. 4, No. 1, February 2009
Explanations affect treatment judgments
and Externally-controlled event conditions, if found,
No event
were due to differential effects of these two types of
events rather than to any of the following plausible alter-
native reasons: (1) greater dissatisfaction with the expla-
nation in one condition relative to the other, (2) increased
perceived hopelessness of treatment in one condition rel-
ative to the other, or (3) increased perception of symp-
tom severity in one condition relative to the other. An
additional 32 undergraduate participants were randomly
assigned to view the vignettes in either the Internally-
controlled (N=16) or Externally-controlled (N=16) con-
dition. For each vignette, they were asked the follow-
Need?for?treatment judgments (1?9)
ing: (1) “How satisfying or unsatisfying is this explana-
tion of the development of [X]’s behaviors?” where 1
= “highly unsatisfactory” and 9 = “highly satisfactory,”
(2) “How quickly or slowly do you believe these behav-
iors would go away with professional psychological treat-
ment?” where 1 = “very quickly,” 8 = “very slowly,” and
Figure 1: Results of the main study. Error bars indicate
9 = “never,” and (3) “How severe or mild do you con-
standard errors.
sider [X]’s overall condition to be?” where 1 = “not at all
severe” and 9 = “very severe.” Equal numbers of partic-
clients’ control. The means for the Externally-controlled
ipants were randomly assigned to see these questions in
condition versus the Control condition ran in the same di-
either the above order or in the reverse of the above order.
rection as the overall results for 7 of the 10 vignettes, and
Vignettes were presented in a different randomized order
of those, 5 comparisons were signi?cant at the .02 level.
for each participant.
We anticipated a stronger effect of Event in the Plausi-
ble than in the Implausible condition. Indeed, there was
3 Results
an interaction of Event and Plausibility (F[2,69] = 4.54;
p = .014; ?2 = .12; see Figure 1). Separate ANOVAs on
the Plausible data and on the Implausible data showed
3.1 Main study
that the main effect of Event was signi?cant in the Plau-
Our questions were (1) whether people who knew the pre-
sible condition (F[2,69] = 8.52; p < .001; ?2 = .20),
cipitating events for clients’ symptoms gave lower need-
and just marginally signi?cant in the Implausible condi-
for-treatment ratings than people who were not given pre-
tion (F[2,69] = 3.08; p = .052; ?2 = .08). Tukey tests
cipitating events for the same clients, and (2) whether
revealed that in the Plausible condition alone, the re-
that effect is dependent on the locus of control indi-
sults mirrored the overall results above (see also Figure
cated in the precipitating event. A 3 (Event; Internally-
1). In the Plausible condition, ratings were lower in the
controlled, Externally-controlled, No event) X 2 (Plausi-
Externally-controlled than in the No-event condition (p <
bility; Implausible, Plausible) ANOVA revealed a main
.001), but did not differ between the Internally-controlled
effect of Event (F[2,69] = 6.18; p = .003; ?2 = .15),
and No-event conditions (p = .301). In contrast, in the
and a Tukey HSD test further indicated that people who
Implausible condition, ratings did not differ between the
had Externally-controlled (M = 5.77, SE = 0.15) precip-
Externally-controlled and No-event conditions (p = .247),
itating events gave lower need-for-treatment ratings than
nor between the Internally-controlled and No-event con-
people who were not given any precipitating event (M =
ditions (p = .687), all as expected.6
6.60, SE = 0.20; p = .006). In contrast, people who had
Finally, we compared how strongly externally-
Internally-controlled (M = 6.50, SE = 0.20) events gave
controlled precipitating events in?uenced need-for-
need-for-treatment ratings that did not differ from ratings
treatment judgments as compared to normality judgments
by people without events (p = .923).5 Having a precipi-
(speci?cally, from Study 2 of Ahn et al., 2003).7 A
tating event reduced people’s perceptions of clients’ need
6There was also a main effect of Plausibility (F[1,69] = 58.61; p
for treatment, but only when the event was outside the
< .001; ?2 = .46). Vignettes with plausible explanations (M = 5.87,
SE = 0.13) were judged to be less in need of treatment than vignettes
5People with Externally-controlled events gave lower need-for-
with implausible explanations (M = 6.72, SE = 0.12; F[1,69] = 58.61);
treatment ratings than people with Internally-controlled events (p =
however, strong conclusions cannot be drawn here, as the content of the
.016). Because the vignettes in these two conditions were of approx-
plausible vignettes differs from that of the implausible vignettes.
imately the same length, it is unlikely that vignette length factored into
7The ?rst author had access to these data as a co-author of the Ahn
people’s judgments.
et al. (2003) paper. As previously discussed, in Ahn et al. (2003),

Judgment and Decision Making, Vol. 4, No. 1, February 2009
Explanations affect treatment judgments
2 (Event; Externally-controlled, No event) X 2 (Judg-
Internally-controlled condition did not differ from those
ment; Normality, Need-for-Treatment) ANOVA showed
in the No-event condition.
that the strength of the main effect of Event was compa-
One might similarly argue that the internally-
rable across studies (that is, there was no interaction of
controlled causes could be perceived as being at the same
Event and Judgment, p = .467; ?2 < .01).
level of explanation as the symptoms, whereas externally-
controlled causes may not. A potential consequence of
3.2 Follow-up manipulation check
this could be that people might ?nd externally-controlled
causes to constitute a more complete or satisfying expla-
The Internally- and Externally-controlled vignettes did
nation than the internally-controlled causes. However,
not differ on any of the follow-up ratings (all p’s > .591;
the results of our manipulation check did not support this
all ?2 < .01). This suggests that the main results were
possibility; people rated the internally-controlled expla-
likely due to the internally-controlled versus externally-
nations as equally satisfying as the externally-controlled
controlled nature of those precipitating events, rather
than to alternative factors (speci?cally, greater dissatis-
faction with the explanations for the internally-controlled
events, increased perceived hopelessness of treatment for
4.2 The rationality of judgments of the
internally-controlled events, or increased perception of
need for psychological treatment
symptom severity for internally-controlled events).
An important outstanding question has been whether it
4 Discussion
is rational to allow increased understanding to in?uence
one’s perception of another person’s behaviors. We sug-
4.1 Summary of ?ndings
gest that the answer to this question depends on the ex-
act judgment being made — that is, whether the judg-
We found that people who were told how a client’s be-
ment being made is about the person’s normality or the
haviors were initially precipitated perceived that client as
person’s need for treatment. In the current study, we
less in need of psychological treatment than did people
found that understanding in?uences need-for-treatment
who were not told how the behaviors were precipitated.
judgments as strongly as it does normality judgments.
Importantly, we also found that the in?uence of increased
But, whereas it may be rational for increased understand-
understanding on need-for-treatment judgments is differ-
ing to affect normality judgments, it may often be less
entially triggered by precipitating events with an external
rational for increased understanding to affect judgments
versus internal locus of control. Because previous work
of the need for treatment.
(on normality judgments) examined only the effects of
With respect to normality judgments, Ahn et al. (2003)
events with an external locus of control, this is a novel
argued that people think of “normal” behaviors as those
?nding in the literature.
occurring frequently in the world. Note that Kahneman
One might argue that the length of the Externally-
and Tversky’s (1982) simulation heuristic suggests that
controlled scenarios relative to the control scenarios
an event is judged to be more likely to occur if a causal
could have driven the difference in need-for-treatment
scenario for that event can be easily constructed (see also
ratings between the two. However, the results of our
the explanation effect; Koehler, 1991). Accordingly, Ahn
plausibility manipulation signi?cantly diminish this pos-
et al. (2003) suggested that the “understanding it makes
sibility, as the implausible vignettes were just as long
it normal” effect may operate in a manner analogous to
as the plausible yet showed no differences; furthermore,
the simulation heuristic, whereby increased understand-
the Internally-controlled vignettes were also longer than
ing of a person’s behaviors may make them seem more
the control vignettes, but no difference between them in
“normal” by making them seem to occur more frequently
need-for-treatment ratings was found.
(Ahn et al., 2003). Interestingly, by this account, it can
It is also unlikely that the locus-of-control effect re-
be rational to allow increased understanding to in?uence
sulted from people perceiving each internally-controlled
judgments of normality. For example, if a person is de-
event as an additional (fourth) symptom. If this had been
pressed because he was diagnosed with cancer, that per-
the case, then people given internally-controlled events
son is literally more normal in the statistical sense. In
should have made signi?cantly higher need-for-treatment
other words, it is true that people diagnosed with cancer
ratings than people given no precipitating events. As we
are statistically more likely to be depressed than people
have seen, however, this was not the case; ratings in the
who are not diagnosed with cancer (Massie, 2004). Al-
though exceptions will occur, we surmise that, in the real
only externally-controlled events were used, so only the Externally-
controlled condition data from the present study could be included in
world, plausible explanations will often tend to coincide
the analysis.
with greater statistical normality in this manner.

Judgment and Decision Making, Vol. 4, No. 1, February 2009
Explanations affect treatment judgments
In contrast, it may often be comparatively less ratio-
that Ted’s girlfriend cheated on him leads Joe to decide
nal to allow increased understanding to lower judgments
that Ted doesn’t need psychological treatment for his ab-
of the need for treatment. Although perceptions of a
normal behaviors after all. Meanwhile, Ted’s symptoms
client’s normality may inform need-for-treatment judg-
and (we presume) ensuing psychological distress have by
ments, from a practical standpoint such judgments should
no means been alleviated. Our ?nding that increased un-
rationally be based upon a combination of considerations,
derstanding reduces judgments of the need for treatment
including not only perceived normality, but also such fac-
may thereby challenge the seemingly logical assumption
tors as the client’s levels of subjective distress and im-
that coming to a better understanding of another person’s
pairment in functioning. For example, people with cancer
problems need always be bene?cial for that person.
who are feeling depressed and people without cancer who
are feeling depressed would both bene?t from receiving
4.3 Psychological versus biological illnesses
treatment for depression, regardless of whether depres-
sion is more common in the ?rst population.8 In such
Another outstanding question of interest is whether we
cases, it would make little sense to downplay the need
should expect to see the same ?ndings in the medical
for psychological treatment with greater understanding
domain. Our speculation is that increased understanding
of the patient’s depressive symptoms. Despite this, par-
will not reduce need-for-treatment judgments in medical
ticipants in our study seemed to behave as though only
conditions; for example, people will probably always rec-
normality was taken into consideration in making need-
ommend medical treatment for a broken leg, regardless
for-treatment judgments.
of whether we know why it was broken in the ?rst place.
It is of particular note that the effect of understanding
Why intuitions might be so different for medical condi-
on normality judgments was of equal magnitude as the
tions and mental disorders is an interesting problem for
effect of understanding on need-for-treatment judgments.
further research. One possibility is that people may be-
One possible interpretation of this ?nding is that people
lieve the primary goal of psychotherapy treatment is sim-
use a very simple heuristic in making need-for-treatment
ply to uncover the source of a person’s problems. Thus, if
judgments, such that treatment is recommended to the
that source has already been discovered, going to therapy
degree that the person seems abnormal. Future work is
may seem futile. In contrast, a medical analogue would
needed to determine whether this is the case, and whether
likely be perceived differently. Suppose that a person is
people can break away from the use of this heuristic if
exhibiting abnormal physical symptoms (e.g., excessive
other important factors are made salient (e.g., the poten-
thirst and blurry vision). People would likely say that
tial bene?ts and purpose of therapy, such as its possible
medical intervention is required to identify the source of
effects on relieving distress and functional impairment).
the problem (e.g., diabetes) but that even once the cause
Again, we argue that allowing increased understanding
of the abnormal symptoms is known and their presence
to affect one’s opinion about a client’s normality is signif-
is more understandable, medical treatment would still be
icantly different from allowing it to affect one’s opinion
required. Thus, whereas identifying the source of the
about the client’s need for treatment. In the ?rst situ-
problem could be considered to be the main goal of a
ation, the reasoner may think, “now that it is more un-
psychotherapy treatment, simply ?nding the source of a
derstandable to me, it seems more normal.” This can be
medical problem may not be perceived as suf?cient.
contrasted with the second situation, in which the rea-
To the extent that people believe this to be true, it may
soner may think, “now that it is more understandable to
be that explanations will only affect perceptions of clients
me, the problem has been solved.” One might speculate
with psychological disorders, and the current ?ndings
that if the clients themselves understood their own be-
may indeed be relatively speci?c to the psychological do-
haviors, the latter case might indeed be rational insofar
main. Relatedly, people hold distinct sets of beliefs about
as clients might better cope with psychological problems
mental disorders that are psychologically versus biologi-
if they knew their cause or source (indeed, in some types
cally caused (Ahn, Flanagan, Marsh, & Sanislow, 2006;
of therapies this might itself be considered to constitute
Ahn, Proctor, & Flanagan, in press). Thus, even within
treatment). However, in this paper we have instead been
the psychological domain, the effect of knowing the pre-
concerned with the speci?c case in which a person other
cipitating event might be stronger for disorders with psy-
than the client has the explanation and is making the as-
chological causes than for those with biological causes.
sessment. In this case, there is no reason why the client’s
behaviors should be assumed to be any less problematic
4.4 Need-for-treatment judgments and the
simply because they are explained in another person’s
mind. To recall our opening example, suppose knowing
clinical domain
8In fact, depression has been shown to negatively affect disease out-
Might the “understanding it makes it normal” effect for
come in cancer patients (Jones, 2001).
treatment judgments also be found in clinicians? Such a

Judgment and Decision Making, Vol. 4, No. 1, February 2009
Explanations affect treatment judgments
?nding might be of particular interest with respect to re-
Ahn, W., Kim, N. S., Lassaline, M. E., & Dennis, M.
ferral decisions (e.g., wherein a primary care physician
(2000). Causal status as a determinant of feature cen-
decides whether or not to refer a client to a mental health
trality. Cognitive Psychology, 41, 361–416.
care practitioner). The effect could also conceivably in-
Ahn, W., Novick, L, & Kim, N. S. (2003). “Understand-
?uence both clients’ and clinicians’ decisions to termi-
ing it makes it normal:” Causal explanations in?uence
nate treatment: as understanding of the client increases,
person perception. Psychonomic Bulletin & Review,
they could be perceived as improving. Once again, if
10, 746–752.
the client understands the problem, it is possible that this
Ahn, W., Proctor, C., & Flanagan, E. H. (in press). Men-
could indeed help them to cope and improve (Pistrang &
tal health clinicians’ beliefs about the biological, psy-
Barker, 1992); however, if the clinician alone understands
chological, and environmental bases of mental disor-
the source of the problems, this by itself has not (yet) in-
ders. Cognitive Science.
?uenced the client’s condition.
American Psychiatric Association. (2000). Diagnostic
The case of clinicians is all the more interesting when
and statistical manual of mental disorders (4th ed., text
a clinician’s approach is principally cognitive, behav-
revision). Washington, DC: Author.
ioral, cognitive-behavioral, or psychopharmacological,
Angermeyer, M. C., Matschinger, H., & Riedel-Heller,
in which case knowing about a precipitating life event
S. G. (2001). What to do about mental disorder —
explanation for a person’s current abnormal behaviors
help-seeking recommendations of the lay public. Acta
should not in theory affect his or her judgments about
Psychiatrica Scandinavica, 103, 220–225.
treatment, in accord with the general philosophies of
Clark, D. A., & Beck, A. T. (1999). Scienti?c foundations
those theoretical orientations (e.g., Clark & Beck, 1999).
of cognitive theory and therapy of depression. New
Speci?cally, these approaches explicitly sidestep the is-
York: John Wiley & Sons.
sue of life-event origins of symptoms (e.g., the psy-
Grasmick, H. G., & McGill, A. L. (1994). Religion, attri-
chopharmacological approach does not distinguish be-
bution style, and punitivness toward juvenile offenders.
tween the effects of different types of life events, in con-
Criminology, 32, 23–46.
trast with a psychoanalytic approach). Instead, these ap-
Jones, R. D. (2001). Depression and anxiety in oncology:
proaches generally focus on the abnormal behaviors (and
The oncologist’s perspective. The Journal Of Clinical
in the case of the cognitive approaches, the abnormal cog-
Psychiatry, 62, 52–55.
nitions) themselves and treatment thereof. The question
Kahneman, D., & Tversky, A. (1982). The simulation
of whether the “understanding it makes it normal” effect
heuristic. In D. Kahneman, P. Slovic, & A. Tversky
is a fundamental cognitive tendency and is found across
(Eds.), Judgment Under Uncertainty: Heuristics and
theoretical orientations, or whether it instead occurs most
Biases (pp. 201–208). Cambridge: Cambridge Univer-
strongly in clinicians with more explanation-oriented ori-
sity Press.
entations (e.g., psychoanalytic or psychodynamic), re-
Kessler, R. C., Berglund, P., Demler, O., Jin, R., & Wal-
mains to be tested.
ters, E. E. (2005). Lifetime prevalence and age-of-
Finally, how might people be trained to avoid the ef-
onset distributions of DSM-IV disorders in the national
fect when necessary? Previous pilot work has suggested
comorbidity survey replication. Archives of General
that the effect may be attenuated by asking people to
Psychiatry, 62, 593–602.
make abstract normality judgments both with and with-
Kikas, E. (2003). University students’ conceptions of dif-
out reference to the explainability of the behaviors (Ahn
ferent physical phenomena. Journal of Adult Develop-
et al, 2003). This ?nding raises the possibility that peo-
ment, 10, 139–150.
ple might immediately see the effect as a fallacy when
Koehler, D. J. (1991). Explanation, imagination, and con-
they are asked to do both. Furthermore, as noted earlier,
?dence in judgment. Psychological Bulletin, 110, 499–
inducing or encouraging people to focus on the poten-
tial bene?ts of treatment may counteract the appearance
Massie, M. J. (2004). Prevalence of depression in patients
of the effect. Additional research will be needed to test
with cancer. Journal of the National Cancer Institute
these possibilities systematically and to discover whether
Monographs, 52, 57–71.
they hold true for judgments of the need for treatment.
Meehl, P. E. (1973). Psychodiagnosis: Selected Papers.
Minneapolis, MN: University of Minnesota Press.
Miresco, M. J., & Kirmayer, L. J. (2006). The persis-
tence of mind-brain dualism in psychiatric reasoning
about clinical scenarios. American Journal of Psychi-
Ahn, W., Flanagan, E. H., Marsh, J., & Sanislow, C.
atry, 163, 913–918.
(2006). Beliefs about essences and the reality of men-
Monterosso, J., Royzman, E. B., & Schwartz, B. (2005).
tal disorders. Psychological Science, 17, 759–766.
Explaining away responsibility: Effects of scienti?c

Judgment and Decision Making, Vol. 4, No. 1, February 2009
Explanations affect treatment judgments
explanation on perceived culpability. Ethics and Be-
Thagard, P. (1989). Explanatory coherence. Behavioral
havior, 15, 139–159.
& Brain Sciences, 12, 435–467.
Pistrang, N., & Barker, C. (1992).
Clients’ beliefs
Thagard, P. (1992). Conceptual Revolutions. Princeton,
about psychological problems. Counseling Psychology
NJ: Princeton University Press.
Quarterly, 5, 325–336.
Read, S. J., & Marcus-Newhall, A. (1993). Explanatory
coherence in social explanations: A parallel distributed
processing account. Journal of Personality & Social
Psychology, 65, 429–447.