Ecole Polytechnique de Lausanne. Switzerland: How does stress affect our self-confidence when we
compete? An EPFL study shows how stress could actually be both a
consequence and a cause of social and economic inequality, affecting our
ability to compete and make financial decisions.
Stress is a staple of our lives today, and we know
intuitively that it can influence our confidence in competing with
others. But how exactly does stress do that? Scientists at EPFL have
carried out the first behavioral study to show how stress actually
affects our degree of confidence, implying that it can even be a cause
of social inequality rather than just a consequence of it. On a
biological level, the researchers have also associated the effects of
stress with the release of the hormone cortisol. The study is published
in Psychoneuroendocrinology.
Confidence is essential to
our ability to compete in society; when we don’t feel confident, we are
less likely to make the kind of decisions that can give us a financial
and social edge over others. By driving social competition, confidence
becomes central in the organization and function of human societies, and
marks the way individuals interact with each other.
At the same
time, little is known about what influences people’s confidence. Two
major factors seem to be stress and the person’s general anxiety.
Technically, this is referred to as “trait anxiety”, and it describes
how prone a person is to see the world as threatening and worrisome. The
question, however, is how stress and trait anxiety impact an
individual’s confidence in a competitive context.
Stress and confidence
The
teams of Carmen Sandi at EPFL and Lorenz Goette at UNIL have now shown
that stress can actually boost the competing confidence of people with
low trait anxiety, but significantly reduce it in people with high trait
anxiety. The scientists designed an elegant behavioral experiment,
which began with more than two hundred people taking two online tests:
one to assess their IQ, and one to measure their trait anxiety.
A
week later, about half of the study’s participants underwent a standard
psychological procedure (called TSST-G) designed to cause acute social
stress, such as going through a mock job interview and performing mental
arithmetic tasks before an impassive audience. The other half of the
participants formed the control group, and did not undergo the
stress-inducing procedure.
All participants, stressed and
non-stressed, were then given two options in a game where they could win
money: they could either take their chances in a lottery, or they could
use their IQ score to compete with that of another, unknown
participant’s; the one with the higher IQ score would be the winner.
In
the non-stressed, control group, nearly 60% of participants chose the
IQ score competition over the lottery, showing overall high confidence
in the participants, regardless of their trait anxiety scores. But in
the group that experienced stress before the money game, things were
different. The competitive confidence of participants varied depending
on their trait anxiety scores. In people with very low anxiety, stress
actually increased their competitive confidence compared to their
unstressed counterparts; in highly anxious individuals, it dropped.
The
findings suggest that stress is a catalytic force acting on a person’s
competitive confidence. Stress, it seems, can raise or suppress an
individual’s confidence depending on their predisposition to anxiety.
Stress and cortisol
The
researchers also found that the effects of stress on the participants’
confidence were mediated by the hormone cortisol, which is normally
released from the adrenal glands, on the top of our kidneys, in response
to stress. The team examined saliva samples from the stressed
participants for the presence of cortisol. In people with low anxiety,
those that showed higher confidence also showed a higher cortisol
response to stress. But in highly anxious people, high cortisol levels
were associated with lower confidence, which connects the behavioral
effects of stress to a biological mechanism.
The findings of this
behavioral experiment can be seen as a simulation of confidence in
social competition and the way it relates to socioeconomic inequality.
Studies have shown that, in areas with wide socioeconomic inequality
(e.g. a wide rich-poor gap), people on the low end of the social ladder
often experience high levels of stress as a consequence.
“People
often interpret self-confidence as competence,” says Carmen Sandi. “So
if the stress of, say, a job interview, makes a person over-confident,
they will be more likely to be hired – even though they might not be
more competent than other candidates. This would be the case for people
with low anxiety.”
Far from being only a product of competitive
inequality, stress must now also be regarded as a direct cause of it. In
other words, stress can become a major obstacle in overcoming
socioeconomic inequality by trapping highly anxious individuals in a
self-perpetuating loop of low competitive confidence.
Carmen
Sandi is now interested in relating the effect of stress on confidence
with brain imaging. Although there is much yet to be learned in this
area, she believes that it can change the way we look at social dynamics
as a whole. “Stress is an important engine of social evolution,” she
says. “It affects the individual, and by extension society as whole.”
This
work represents a collaboration of EPFL with the University of Lausanne
(UNIL). The study was partly sponsored by the Swiss National Science
Foundation.
Reference
Goette L, Bendahan S, Thoresen J, Hollis F, Sandi C. Stress pulls us apart: Anxiety leads to differences in competitive confidence under stress. Psychoneuroendocrinology 18 February 2015. http://dx.doi.org/10.1016/j.psyneuen.2015.01.019