Riskperception – modeller och
principer
The Swedish Risk Academy
Annual Meeting
May 14, 2013
Lennart Sjöberg
Center for Risk Research
Stockholm School of Economics
Sweden
Outline
•
•
•
•
•
•
•
•
•
•
Why study risk perception?
Experimental work
Factors in risk perception
Specifics of risk perception: example of chemicals
Trust and antagonism
Risk targets
Demand for risk mitigation
Affect (attitude) and emotions
Experts and the public
Conclusions
2
As you will see,
my research questions the “received view”
from well-known work on risk perception,
critical comments are invited
Why research on risk
perception?
• Risk is a very common issue in policy deliberations
• This is true both for decision makers, experts and the
public
• Several risk related issues have created great economic
and political turbulence
• There is therefore a need to know more about how
people perceive and react to risks
4
Risk perception (RP) and risk
communication (RC)
• Beliefs (”perceptions”) constitute the basis:
What RC should be about
• Beliefs are both the motives for RC and
targets of RC
• The sucess of RC is therefore dependent
on the validity of RP models applied
5
Some experimental work
• Does exposure to well crafted “risk movies” lead
to availability of the risks depicted, and hence to
increased perceived risks
– To our surprise no such effect could be found!
• A similar theme was studied in a quasiexperiment in 5 countries where we followed
media reports on nuclear risks 10 years after the
Chernobyl accident. Intense media attention
should have increased availability and hence
perceived risk.
– To our surprise no such effect could be found!
Interpretation
• What looks like availability effects is really
effects of new information, cp. the news
about “mad cow disease” in the spring of
1996. This was NEW information and it
had great RP effects.
• Just bringing up an old and well known
risk does not make it see more
threatening.
Data sources (examples) from our work on risk
perception surveys at the Center for Risk
Research in Stockholm
• Several projects on attitudes and perceived risks with regard to
nuclear power and nuclear waste – both EU and Swedish data
• EU project on chemicals in consumer products
• Perceived risk of food, genetically modified food, alcohol and
smoking
• Political and social risks of EU membership
• Perceived risks of terrorism
• Selected results from surveys will be presented, but first some
experimental work on availability…
8
Surveys: Factors in risk perception
• ‘Interfering with nature’ is an important factor and so are moral
aspects
• Reactions to new technology are not driven by ‘novelty’ per se but
by other factors, such as perceived benefit, or whether the
technology brings about unique advantages and is hard to replace
• Social trust is important, but epistemic trust, trust in Science, is
even more so
• Attitude or ”affect” plays an important role
• Risk sensitivity is an aspect of individual differences which is quite
important – some people rate risks as large, others rate them as
small
• Attitude to precautionary policy is another important factor
• Various hazards, some new (such as terrorism), require their own
specific factors
9
10
Typically social trust (in
experts or organisations) has
only a weak effect on
perceived risk – correlations
of 0.3 or less
But at the aggregate level it is
easier to see a relationship.
See graph based on surveys
of chemical risks, next slide
11
12
Factors beyond social trust
• Trust in science, as distinct from social trust, has a
stronger effect – epistemic trust
• Level of education is also important
• Another important factor is perceived antagonism
13
Effect of social trust is mediated by
epistemic trust (model of nuclear waste risk)
Risk
sensitivity
0.28
-0.23
-0.22
R2=0.41
R2=0.37
0.35
0.38
Social
trust
-0.50
Epistemic
trust
R2=0.56
-0.51
Perceived
risk
-0.19
0.12
Antagonism
GFI=0.95, AGFI=0.93, RMSEA=0.030
14
Conclusion about trust
• Epistemic trust is more important than social trust
• The effect of social trust is mediated by epistemic
trust
• In other words: trust in people and institutions is
important to the extent that it promotes belief in the
substance of their message
15
Risk target: Whose ‘risk’ – more specifically?
• Personal and general risk differ both as to level and rank
order
–General risk is important for lifestyle (smoking etc.,)
–Personal for environmental risks, and technology hazards
• Research shows that such risk ratings with a non-specified
target are close to general risk
• But, general risk is not the most relevant in policy contexts
16
Ge ne ra l risks ra te d a s m uch la rge r tha n
pe rsona l risks
datfromhepublic.
Mean general risk
6
5
4
3
Regression line
2
y=x
1
0
0
1
2
3
4
5
6
Mean personal risk
17
Personal and general risk, alcohol
Mean risk rating
5
4
3
Personal risk
General risk
2
<15
16-20
21-37
38-75
75+
Alcohol consumption per week (corresponding to cl vodka)
18
Personal and general risk, smoking
Mean risk rating
5
4
3
Personal risk
General risk
2
<12
13-20
21-30
31-55
Number of cigarettes per day
19
Different dynamics of personal and general
risk
• General risk is related to policy for hazards perceived
to be under one’s personal control
• Personal risk is related to policy for hazards not under
one’s personal control
• Examples: alcohol and nuclear power
20
21
How important is ”risk”?
22
Focus on risk – traditional approach
• People are asked to rate the ‘risk’
• It is assumed that perceived risk, as defined in this
way, is the factor driving risk-related behaviour – such
as demand for risk reduction
• But the assumption is usually implicit
23
Risk mitigation – the problem
• What drives demand for risk reduction?
• Is perceived risk the important factor?
• If not, what factor is most important ?
24
Example
• Consider the risk for a Swedish citizen, age 30–45, to
1. get a severe cold during the next 12 months
2. become infected with the HIV virus during the same
time period
• Which risk is the largest?
• From which risk is it more important to be protected?
25
Risk perception studies show that
• Risk and probability are closely related
• Severity and demand for risk reduction are closely related
• Risk and demand for risk reduction are only moderately
related (“probability neglect”)
26
Implications
• In risk communication it should be clear that the public
wants to hear about severity of consequences, not so much
about probabilities:
–Probability is hard to understand
–Precise estimates of very small probabilities must rely on
many assumptions and are seldom very credible
• In risk perception research, it is necessary to broaden the
scope – just studying ‘risk’ is not sufficient
27
Individual differences in risk perception
28
Distribution of
the number of
product types
checked as risky,
across all
respondents.
29
”Risk sensitivity” or attenuation- amplification
of perceived nuclear waste risk
30
The level of risk judgments varies strongly
across individuals
and is a very important explanatory factor
in risk perception models:
Risk Sensitivity
31
Specific risk factors
32
Recent EU project on perceived risks of chemicals
in consumer products (extensive data collected in
the beginning of 2009)
•
•
•
•
N=26,718
All 27 member states of the EU participated
Among other things, participants were asked:
According to what you know, which of the following
consumer products contain chemicals posing a risk
to the user?
• 13 product categories were listed
33
Specific reactions, not to general concept
Pesticides or herbicides
Bleach and heavy duty cleaners
Bathroom cleaners
Hair dyes
Interior paints
Timber preservatives
Laundry or dishwashing detergents
Washing powder
Fabrics: Synthetic fibers
Sunscreens
Hair shampoo
Fabrics: Wool cotton or linen
Toothpaste
0
20
40
60
80
Percentage check a product category, all states
34
Comment:
”Chemicals” is a highly variable concept.
Sometimes very risky, sometimes not.
35
Study of the perceived risk of
terrorism
36
Conclusion
• Traditional explanatory factors (dread and
new risk), as well as background factors,
only explained 10-15 % of the variance of
perceived risk
• Twice that level was reached by adding
specific factors
Emotions and affect
• “Affect” is a word with several distinct meanings:
emotions or values (attitudes)
• It is necessary to clarify which one is investigated –
they are psychologically quite different
• Both are related to risk perception
38
Attitude (affect), trust, risk sensitivity
and attitude towards nuclear power (1991 study)
39
Emotions – study of emotional reactions to a
nuclear waste repository
• Two candidate municipalities, one control and a national
sample
• About 800 respondents from two communities where site
studies are now carried out
• Several emotions were rated, not only one
• Negative and positive emotions were rated
40
Model of the attitude to a nuclear waste repository
Model of attitude to the repository explaining 65% of the variance
Attitude to
nuclear power
Social
trust
0.06
Positive
emotions
0.13
0.26
Attitude to
the
repository
- 0.21
Negative
emotions
0.18
Epistemic
trust
- 0.16
Risk to the
municipality
41
Correlations between emotional reactions and the attitude to
nuclear power
Emotion
Own emotional reaction to
nuclear power
The anticipated emotional
reaction of others to nuclear
power
Anger
-0.62
-0.08
Contempt
-0.55
-0.10
Fear
-0.65
-0.06
Interest
0.28
0.17
Sadness
-0.58
-0.12
Satisfaction
0.57
0.21
Guilt
-0.25
0.03
Shame
-0.29
0.04
Worry
-0.61
-0.12
42
Mean emotional reactions attributed to others versus own
reactions
Others’ emotional reaction
3.5
3.0
2.5
2.0
1.5
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
Own emotional reaction
43
A methodological point
• Instructions to rate “dread” do not specify WHOSE
dread
• This probably leads to the interpretation to rate the
emotional reactions of OTHERS
• In turn, data therefore reflect only a weak link between
emotional reactions and perceived risk
44
Conclusions about emotions
• Specific and current emotional reactions do seem to
explain much of attitudes and policy behaviour, attitude
(“affect”) somewhat less
• Compare these strong effects with the almost zero
importance of anticipated ‘dread’ of others
• Both positive and negative emotions are important
• Note that ‘worry’ contributes beyond the effect of ‘fear’
• Anger seems to be more important than fear in policy
contexts
45
Experts versus the public
• Original work suggested, in some interpretations, that
experts make ‘correct’ and ‘objective’ risk judgements
used a very small group of ‘experts’ with questionable
competence
• Later work with substantive experts has shown that
they have similar structure of risk perception, but lower
level
• Risk perception is related to experts’ field of
responsibility – not to knowledge
46
Ratings of risk dimensions of nuclear waste
by the public, and male and female experts
5
A
5
B
4
4
3
Meanratingsbyfemaleexperts
Meanratingsbymaleexperts
3
2
1
0
2
1
0
1
2
3
4
M
e
a
nra
tin
g
sb
ym
e
n
,m
e
m
b
e
rso
fth
ep
u
b
lic
5
1
2
3
4
5
6
M
e
a
nra
tin
g
sb
yw
o
m
e
n
,m
e
m
b
e
rso
fth
ep
u
b
lic
Expert-public difference for both genders
47
4.0
No gender
difference
among
experts
Mean ratings by male experts
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Mean ratings by female experts
48
Regression coefficients in model of perceived nuclear waste
risk, results from analyzing data from experts (A) and engineers
(B) plotted against results from analyzing data from the public.
0
.4
0
.4
B
0
.3
0
.3
0
.2
0
.2
Regresioncoeficients,enginers
Regresioncoeficient,experts
A
0
.1
0
.0
0
.1
0
.0
0
.1
0
.2
R
e
g
r
e
s
s
io
n
c
o
e
f
f
ic
ie
n
t
,p
u
b
lic
0
.3
0
.4
0
.1
0
.0
0
.1
0
.1
0
.0
0
.1
0
.2
0
.3
0
.4
R
e
g
r
e
s
s
io
n
c
o
e
f
f
ic
ie
n
t
s
,p
u
b
lic
Very similar models for experts and the public
49
Correlations between risk perception ratings and
the psychometric factors (genetically modified food)
for the public and experts
Personal risk
Explanatory variable
General risk
Public
Experts
Public
Experts
Dread
0.40
0.43
0.19
0.01
New risk
0.44
0.51
0.31
-0.06
Interfering with nature
0.47
0.53
0.47
0.08
Immoral risk
0.51
0.56
0.61
0.38
Severity of consequences
0.50
0.54
0.47
0.08
Epistemic trust
-0.24
-0.31
-0.27
-0.08
Social trust
-0.38
-0.42
-0.52
-0.30
Experts’ risk ratings unrelated to “subjective factors,
But only for Dread and Novelty and for general risk
50
Conclusion – public and experts
• Experts judge personal risk in a manner similar to the
public
• However, their judgements of general risk seem to be
less correlated with the ‘subjective’ factors
• Other studies have shown that personal risk is most
important in policy related to technology and the
environment
• Experts judge risks to be smaller when they are within
51
their general area of responsibility
What does our research imply for risk
communication?
• Emotions are important to take into account
– but not only strong fear
• Concern about ‘Interfering with Nature’ is a major factor
– but not novelty of a risk
• People’s understanding and trust in science is very important
– social trust is somewhat less important
• ‘Risk’ and ‘probability’ are marginal to people
– they respond to notions about anticipated consequences and
whether a technology has unique advantages
• Experts are not that different from the public in how they react to
hazards outside their field of responsibility
52
For more information…
•See my homepage
http://www.dynam-it.com/lennart/
•Several papers and reports can be
downloaded from that site
53