Poverty saps mental capacity to deal with complex tasks, say scientists

Poor people spend so much mental
energy on the immediate problems
of paying bills and cutting costs
that they are left with less capacity
to deal with other complex but
important tasks, including
education, training or managing
their time, suggests research
published on Thursday.
The cognitive deficit of being
preoccupied with money problems
was equivalent to a loss of 13 IQ
points, losing an entire night's sleep
or being a chronic alcoholic,
according to the study. The authors
say this could explain why poorer
people are more likely to make
mistakes or bad decisions that
exacerbate their
financial difficulties.
Anandi Mani, a research fellow at
the Centre for Competitive
Advantage in the Global Economy
at the University of Warwick, one
of the four authors of the study,
said the findings also suggest how
small interventions or "nudges" at
appropriate moments to help poor
people access services and
resources could help them break
out of the poverty trap. Writing in
the journal Science , Mani said
previous research has found that
poor people use less preventive
health care, do not stick to drug
regimens, are tardier and less
likely to keep appointments, are
less productive workers, less
attentive parents, and worse
managers of their finances. "The
question we therefore wanted to
address is, is that a cause of
poverty or a consequence of
She said the team of researchers,
which included economists and
psychologists in the UK and the US,
wanted to test a hypothesis: "The
state of worrying where your next
meal is going to come from – you
have uncertain income or you have
more expenses than you can
manage and you have to juggle all
these things and constantly being
pre-occupied about putting out
these fires – takes up so much of
your mental bandwidth, that you
have less in terms of cognitive
capacity to deal with things which
may not be as urgent as your
immediate emergency, but which
are, nevertheless, important for
your benefit in the medium or
longer term."
To test their idea, the team carried
out two sets of studies.
In the first they approached around
400 people at random in a
shopping mall in New Jersey and
asked them to think about how they
might solve a financial problem.
Volunteers were given an "easy"
scenario, where the cost of a car
repair was around $150, and a
"hard" scenario, where the repair
would cost more like $1,500.
While they thought about this, the
volunteers took part in puzzle-
based IQ tests and tasks that
measured their attention.
The researchers compared the
change in performance in the tests
for rich and poor people across the
two scenarios, with rich and poor
defined as being either side of the
median US household income of
$70,000 per year.
In the second study, the team
carried out IQ and attention tests
on 464 sugar cane farmers in
Tamil Nadu in India during
cyclical conditions of relative
wealth and poverty. Because of the
long crop cycle for sugar cane,
farmers tend to be poor just before
a harvest and relatively well off a
few weeks after the harvest, when
they have received their annual
crop earnings.
In the shopping mall experiment,
rich and poor people performed
equally well on the "easy"
But poorer people performed much
worse on the "hard" scenario –
their average IQ was 13 points
lower when they were thinking
about serious financial troubles.
"That's the difference in IQ
between a person who is a normal
adult versus a chronic alcoholic,"
said Mani. "In terms of age, it's
like an average 45-year old as
opposed to an average 60-year-old.
In terms of sleep loss, [the
immediate impact of the mall
study] is like losing a full night of
For the Indian farmers there was a
similar but smaller effect.
"What we did is look at the same
people the month before and the
month after the harvest, and what
we see is that IQ goes up, cognitive
control, or errors, goes way down,
and response times go way down,"
said Sendhil Mullainathan, a
professor of economics at Harvard
University and a co-author of the
study. "The effect here is about
two-thirds of the size of the effect
found in the mall study – it's at
least nine or 10 IQ points, just
between these months."Between
these two studies, you both see the
mechanism at work, and you see
that, in the real world, these effects
are enormous.In their study, the
researchers controlled for possible
mitigating factors such as stress,
quality of nutrition, available time
and also the fact that people can
sometimes get better at cognitive
tests once they have tried them out
a few times.
Mullainathan added that "the
results are not suggesting that the
poor as people have less cognitive
capacity but that anyone
experiencing poverty would have
less capacity. I realise this is basic
but it is such an easy mistake to
make in interpreting the
Jennifer Wild, a clinical
psychologist at the University of
Oxford , who was not involved in
the study, said the latest results
were novel because, previously,
researchers "may have thought that
environmental conditions, such as
lower levels of education,
explained the link between poverty
and poorer performance on some
tasks of intelligence compared to
the rich."
She added that a limitation of the
study was that the researchers had
not studied how the financial
questions in the shopping mall
scenario had affected the
emotional states of the
participants. The $1,500 amount in
the "hard" scenario may have
failed to influence the cognitive
processing of participants with
higher incomes because it might
have been too low to be meaningful
to them, she said.
"The figure of $1,500 may have led
to anxiety in low income
participants, which could have
influenced their performance. The
study failed to look at affective
state. How much anxiety did the
imagined scenarios create and
were their differences in how
anxious high and low income
participants felt, which could
explain there differences in
Mani said that the results of the
study had implications for
policymakers. "When we think of
poor people and design policies and
programmes to help them, we are
only particularly cognizant of the
fact that they have less material
resources," she said. "I think that
programmes don't often appreciate
that they're also, precisely because
of poverty, a bit challenged in
terms of the mental resources and
attention that they have. To the
extent that we want to make anti-
poverty programmes effective, we
want to design them in a way that
is mindful of that."
This could mean helping poorer
high school students fill in
application forms for financial aid
rather than leaving them to do it by
themselves. Rather than assuming
that many of the poor are not
taking advantage of beneficial
schemes through lack of motivation
or interest, said Mani, help with
"small nudges at the right time and
limiting the amount of cognitive
load that become barriers to them
enrolling in the programme could
make a big difference."
Other kinds of help could include
sending text reminders to take pills
or deposit money for a specific
savings goal they have, said Mani.
"When they have 20 things that are
grabbing their attention, which
seem very urgent, to remind them
of something that's important at the
right time, that's also an effective