Vol.3, No.4, 206-210 (2011) Health
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
Infectious diseases and interpersonal trust:
international evidence
Diego Gonzalez-Medina1, Quan V. Le2*
Seattle University, 901 12th Avenue, Seattle, USA; *Corresponding Author: lequ@seattleu.edu
Received 18 January 2011; revised 23 March 2011; accepted 27 March 2011.
The objective of this paper is to investigate the
relationship between infectious disease and
trust, hypothesizing a negative relationship. In-
terpersonal trust is defined as the aggregate
response that fellow citizens are trustworthy.
We explore stigma as a channel in the relation-
ship. We apply cross-country regression analy-
sis on a sample of 54 countries. We test our
hypothesis using data on selected infectious
diseases from the World Health Statistic s ( WHS)
published by the World Health Organization
(WHO) and data on trust from the World Values
Surveys (WVS). We cre ate an index of infectious
disease using factor analysis. The OLS regres-
sion equation includes control variables of in-
come inequality, per capita income and human
capital. The empirical results are considerably
robust showing that higher cases of infectious
diseases are negatively associated with trust
when controlling for macroeconomic and social
Keywords: Trust; Stigma; Social Capital; Infectious
Disease; HIV/AIDS
The topic of trust is relatively new to the field of so-
cial science and public health. Trust positively facilitates
our social institutions, which rely considerably on col-
laboration. In their seminal paper on trust and growth,
Zak and Knack [1] explain trust as a driver for lowering
transaction costs by reducing oversight costs with as-
sumed aggregate effects. It can do this because trus t is a
force behind social capital formation rewarding coordi-
nation within social structures. Wang et al. [2] define
trust as a form of cognitive social capital, meaning that it
predisposes people to work in a mutually beneficial man-
ner. Their research shows that there is strong and com-
plex relationship between trust and health [2], which we
seek to investigate further. In this paper we focus on this
relationship in the context of in fectious disease. Previous
literature has provided strong empirical evidence that
social support promotes preventative action and treat-
ment of infectious disease [2,3]. Our objective is to in-
vestigate the correlation of infectious disease and aggre-
gate trust levels, hypothesizing a negative relationship.
Using a sample of 54 countries, we test our hypothesis
using data on selected infectious diseases from the World
Health Statistics (WHS) published by the World Health
Organization (WHO) and data on trust from the World
Values Surveys (WVS).
In previous studies, relationships between trusting
behavior and infectious disease were examined in the
context of public health [2-7]. Though samples were
limited to specific coun tries or diseases, stigma rose as a
common theme. The interaction between infectious dis-
ease, stigma and trust implies stigma as the main actor
between the others.
Stigma is created from “an attribute that is deeply dis-
crediting” of the infected population, provoking mistrust
or sympathy, fear or support [8]. Where interpersonal
trust is a reward of social collaboration, stigma disrupts
it by invoking widespread prejudice, discrimination and
disregard against infected members of society and those
associated with them [9]. Thus, the presence of stigma
undermines trust on an individual level, with assumed
aggregate effects1. Yet, stigma also leads infected people
to conceal their disease and making it unlikely for them
to seek testing, treatment and support [3]. Such inaction
generally increases the load of infectious disease since
effective treatment is not taken. Therefore, stigma has
the power to both undermine aggregate trust and in-
crease a country’s incidence of infectious disease.
The research on the stigma surrounding tuberculosis
1We elevate the relationship between stigma and interpersonal trust up
to aggregate trust levels because stigma, by definition, must be widely
held. Otherwise, it is indistinguishable from individual prejudice.
D. Gonzalez-Medina et al. / Health 3 (2011) 206-210
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
in Nepal and Somalia illustrates how a widespread dis-
ease can sabotage interpersonal trust [6,8]. Since tuber-
culosis is a curable disease, it b enefits highly from effec-
tive social institutions. These would have the effect of
expediting successful identification and treatment of
tuberculosis. In one interview from the study, support is
clearly lacking: “…they want that you also have
TB…because they know that they will be isolated and
they become very vindictive. They want everyone to have
it…He will trick you…the person with TB will drink, spit
inside and throw the rema ining back in the pot…” [6]
Previous studies in Nepal, Réunion Island, and of
Caribbean immigr ants in the Un ited Kingdo m found fear
of contamination and presence of stigma [5,7,8]. One
woman from the Caribbean expressed how it caused her
to lose her job as a teacher: “Youve got AIDS. I don’t
want nobody to come and burn my school down, so it’s
best if you leave.”[5]
Left to its own devices, widespread mistrust and fear
can introduce discrimination into the healthcare system.
This has large implications for the spread of infectious
diseases. For example, breaches of confidentiality and
refusal to exam an infected patient leads to delays in
treatment or complete evasion [5]. When social institu-
tions like these become a source of discrimination, the
infected are left on their own to find support [9]. Thus it
is clear that stigma has the effect of both diminishing
trust and raising levels of infectious disease. And given
its dominance in previous studies, it is assumed to be the
main actor behind the negative relationship between trust
and infectious disease.
In the following sections, we provide cross-national
evidence displaying a negative relationship between in-
fectious diseases and aggregate levels of interpersonal
trust. Following the two-tier methodology of Zak and
Fakhar [10], we use WVS data on interpersonal trust to
capture generalized trust and test it against country level
data of infectious diseases. We are, in essence, testing whe-
ther trust (at a personal level) has a relationship with
infectious disease that scales up to the country level. Ex-
planatory variables of per capita income, income ine-
quality and human capital are also taken into account.
Specifically, we use secondary education enrollment as
an adequate proxy for human capital, citing previous
growth literature [11].
We attempt to provide testable implications of our
hypothesis using relevant data on infectious diseases and
interpersonal trus t in a cro ss-section of countries. We use
second level data on selected infectious diseases from
the World Health Statistics (WHS) published by the
World Health Organization (WHO) in 2009 [12].2 There
are 18 officially reported infectious diseases based pri-
marily on the availability of data in 2007.3 This is the
most comprehensive data available despite its limita-
tion.4 The International Health Regulations reported
some diseases, while countries and the WHO monitor
other diseases in the context of specific control programs
[12]. The database reveals that the Eastern Mediterra-
nean region has the highest cases reported, while the
region of the Americas has the lowest number of cases
reported. The database also reports that lower middle
income group has the highest number of cases reported,
while the high income group has the lowest number of
cases reported.
Because the dataset includes a large number of infec-
tious disease cases, examining them one-by-one does not
provide sufficiently strong evidence to test the relation-
ship between infectious diseases and interpersonal trust.
It is more feasible to construct a statistical indicator us-
ing data reduction method on the cases of infectious
diseases. We construct an index of infectious diseases by
employing factor analysis. Principal component analysis,
the most common form of factor analysis, is used to ex-
tract the first principal component based on the largest
The data on trust are obtained from the World Values
Surveys (WVS) 1990-2000 [1,13-15]. The WVS con-
tains data from thousands of respondents from both de-
veloping and developed countries.5 The respondents in
each country respond to the question using the native
language, and the questions correspond to impressions of
the respondents’ own countries: “Generally speaking,
would you say that most people can be trusted, or that
you cant be too careful in dealing with people?” This
question captures “interpersonal trust”, describing whether
two randomly selected individuals trust each other. This
general phrasing of trust captured in the WVS survey
question suggests that this is a reasonable cross-country
measure of trust. This trust variable has been used in a
2World Health Statistics (2009), Table 3: Selected Infectious Diseases,
p. 59-69. Geneva: WHO. The numbers are officially reported, but
vary greatly in quantity, representatives, comparability and informa-
tion value (WHS, p. 5 9 , 2009).
3H5N1 influenza cases were reported in 2008. WHS differentiates
between zero cases reported and no information available for a country
where possible.
4There is a limitation when using this dataset. WHO recognizes tha
there are inadequacies in the measurement of cases of infectious dis-
eases [12]. The report states that it is difficult to understand the sever-
ity of infection in a country solely by the recorded number of occur-
rences. This inadequacy can be due to the nature of the disease itself or
due to the nature of data collection [12]. In addition, the disease itsel
can be difficult to report (e.g. H5N1 influenza, Japanese encephalitis)
without specific laboratory testing that is not always available [12].
Depending on the country, data collection can also be a significan
5See the WVS’s website for further technical information about the
questionnaire at: www.wordvaluessurvey.org.
D. Gonzalez-Medina et al. / Health 3 (2011) 206-210
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
cross-country contex t in several studies [1,10,13] despite
its limitation. 6 Given the availability o f the data fro m the
WVS, we are able to compare the levels of trust to cases
of infectious diseases across countries in this study. The
data vary noticeably between 54 rich and poor countries.
In poor countries such as Uganda, Tanzania, and the
Philippines, less than 10% of the respondents say their
fellow citizens are trustworthy, more than 65% of the
respondents in Sweden and Denmark believe this is so.
If societies are at high risk of contracting deadly dis-
eases from the afflicted individuals, stigma and dis-
crimination can sabotage interpersonal trust. Thus, high
scores on the infectious disease index are associated with
lower trust levels. For instance, the trust levels in Swe-
den and Denmark are remarkably high with low scores
on the infectious disease index, whereas the trust levels
in Uganda, Tanzania, and the Philippines are considera-
bly low with high scores on the infectious disease index.
We also utilize other explanatory variab les that have a
strong effect on trust such as per capita income [13]. Per
capita income is expected to take a positive sign. Other
variables also included in the regression analysis are
income inequality and the level of human capital. In-
come inequality plays a role in discouragement of social
cohesion amongst individuals causing class distrust
through polarization [16]. Thus, societies with high in-
come inequality exhibit lower trust. We used the Gini
coefficient of income as a proxy for income inequality.
The sign is expected to be negative. Human capital ef-
fects trust in the way that it enhances social networks
and presents rewards for integrity. These rewards given
on the basis of meeting performance criteria with integ-
rity establishes the fundamental social infrastructure for
trust upon which an eco nomy can be built. We used per-
centage of gross secondary school enrollment as a proxy
for human capital. Secondary education provides not
only the tools of reading, writing and mathematics, but
also lays the foundations of on-going learning and de-
velopment, allowing individuals to make constructive
criticisms and rightful judgments. This leads us to expect
human capital to take a positive sign. Data for per capita
income, Gini coefficient, and gross secondary school
enrollment are the taken from the World Development
Indicators [17].
In this paper we hypothesize that societies with high
levels of infectious diseases are more likely to respond,
in aggregate, that their fellow citizens are less trustwor-
thy. Table 1 reports OLS regressions of infectious dis-
eases on trust controlling for other explanatory variables.
In equation 1, the index of infectious diseases explains
10% of the variation in trust. The coefficient estimate for
infectious diseases has a negative and significant effect,
as hypothesized. In equation 2, the infectious disease
index remains statistically significant with the expected
sign when per capita income is included in the regression.
By adding per capita income to the regression, the ex-
planatory power increases to 34% of the variation in
trust. Income inequality is added to equation 3 as a con-
trol variable. The result shows that the index of infec-
tious diseases has a negative and remains statistically
significant per expectation. The coefficient on income
inequality is negative and significant, suggesting dispar-
ity in income decreases the levels of trust. This equ ation
explains 20% of the variation in trust. Last but not least,
when human capital is taken into account in equation 4,
the infectious disease index has a negative, but insig-
nificant effect on trust. However, per expectation, the
coefficient on secondary education is positive and sig-
nificant, suggesting that the skills attainted in secondary
school are poised to develop critical thinking that are
necessary for trust to triumph through truth.7 This equa-
tion explains 29% of the variation in trust.
Table 1. OLS Regression: Infectious Diseases on Interpersonal
Trust (excluded HIV/AIDS/STIs cases)
variables (1) (2) (3) (4)
Constant 12.278**
(5.312) 10.832**
(4.571) 39.099**
(11.263) –7.606
Infectious diseases –58.718***
(22.266) –33.065*
(20.069) –40.098*
(22.806) –0.792
Per capita
income 0.001***
No. of
observations 54 53 50 52
Adjusted R2 0.10 0.34 0.20 0.29
Notes: The dependent variable is Interpersonal Trust. White heteroskedas-
ticity-constant standard errors in parentheses. ***Significant at 1%; **sig-
nificant at 5%; *significant at 10%.
6For example, Wang et al. [2] survey trust by measuring levels o
trustworthiness and mistrust separately. They find that a low level o
trust does not necessarily mean a high level of mistrust. They suggest
that when surveying trust, researchers asking questions regarding trust
should be careful to separate those emphasizing mistrust from those
emphasizing trust and report them differently. This is because their
research shows that the effects of low levels of trust can differ from
those of hi
h mistrust
7We also included primary education in the regression.The result
reveals that the infectious disease index has a negative and significant
effect, as expected. However, the coefficient on primary educationis
negative and insignificant. Possible explanation for this is that primary
education is more universal than secondary education across countries.
Thus, secondary education was much more effective in explaining
D. Gonzalez-Medina et al. / Health 3 (2011) 206-210
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
Table 2. OLS Regression: Infectious Diseases on Interpersonal
Trust (included HIV/AIDS/STIs cases).
variables (1) (2) (3) (4)
Constant 16.691***
(3.882) 12.666**
(3.297) 42.630***
(11.468) –7.291
diseases –40.052***
(15.454) –21.913*
(13.286) –22.112*
(12.784) –4.479
Per capita
income 0.001***
No. of
observations 52 51 49 51
Adjusted R2 0.10 0.40 0.20 0.29
Notes: The dependent variable is Interpersonal Trust. White heteroskedas-
ticity-constant standard errors in parentheses. *** Significant at 1%; **
significant a t 5 %; * s i gnificant at 10%.
WHO does not report HIV/AIDS/STIs in the WHS
[12], yet it is one of the serious infectious diseases.
Stigma and discrimination are common problems facing
people living with HIV/AIDS/STIs. Because of such
stigma and discrimination, HIV/AIDS/STIs is in turn
associated with decreased trust. We extend our analysis
to include HIV/AIDS/STIs in the principal component
analysis to extract a new index of infectious diseases.
The OLS regression results are reported in Table 2 with
the new index. In equation 1, the index of infectious
diseases is significantly correlated with trust per expec-
tation at the 1% level. This equation explains 10% of the
variation in trust. The index of infectious diseases re-
mains negative and statistically significant at the 10%
level when income per capita is included in equation 2.
This equation explains 40% of the variation in trust.
When income inequality is added to equation 3, the in-
dex of infectious diseases remains robustly significant at
the 10% level. When human capital is tak en into accou nt
in equation 4, the infectious disease in dex has a negative,
but insignificant effect on trust.
The statistical results indicate that high levels of in-
fectious diseases have a significant effect on lowering
trust levels, suggesting that infectious diseases can sa-
botage interpersonal trust causing a decline in social
The empirical results indicate that higher cases of in-
fectious diseases are negatively associated with trust in a
sample of 54 countries with robust estimates. The find-
ings are strong enough to motivate a shift in perspective
when studying factors of infectious disease. We seek to
underscore the relevance of social capital in this discus-
Specifically, the literature surveying experiences of
infected people suggests that stigma and low interper-
sonal trust are caused by factors of fear and perceived
threat of infection [3,4,6,8,9]. And since risk perception
necessarily precedes stigma, we affirm that it is the in-
cidence and subsequent risk perception that causes stig-
matizing reactions and falling levels of interpersonal
Targeting stigma, as the literature suggests, may be an
effective measure to improve interpersonal trust and de-
crease infectious disease. Targeting stigma enhances in-
terpersonal trust through open dialogue and approval of
social bonds once broken by stigma. Similarly, targeting
sources of stigma reduces the levels of infection diseases
by making healthcare more approachable and trustwor-
thy in areas where healthcare was once a source of stigma.
To reap the benefits of trust, efforts are required to coun-
teract discrimination and stigma against those targeted.
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