How do we define poverty? It is sometimes said that real poverty is rare in Western societies where even people on low incomes may have mobile phones and flat-screen televisions. But with ongoing cuts in welfare benefits and the use of charitable food-banks dramatically increasing, it is difficult to ignore recent findings that demonstrate the major impact that money worries have on our intelligence.
Being brought up in poverty is a known risk factor for impaired brain development, which can impact on thinking and reasoning skills in adulthood. But the immediate effect of poverty on intelligence has only recently been demonstrated, in a psychology study boldly entitled “Poverty Impedes Cognitive Function”.
This research is particularly compelling because two distinct strands of work – one in a laboratory in New Jersey, USA, and one amongst sugar-cane farmers in Tamil Nadu, southern India – both showed that performance on problem-solving tests can be affected by financial concerns. The drop in intelligence due to immediate poverty was as much as 13 IQ points, comparable to the effects of chronic alcoholism or missing a whole night’s sleep.
In New Jersey, shoppers recruited in a mall were presented with hypothetical scenarios requiring a decision about spending money, for example, whether to repair a faulty car. The required outlay was varied, so that getting the car back on road could cost $150 or $1500. Whilst the participants were thinking about these plausible scenarios, they were asked to complete two tests of cognitive function.
One test – Raven’s Matrices – is a standard way of measuring logical thinking and the ability to solve novel problems, what is broadly called “fluid intelligence”. The other was a variant of the classic Simon task, where participants have to respond to a visual figure by touching a screen. In the “spatial incompatibility” case, the required response is in a different location to the stimulus, presenting a challenge to participants’ cognitive control.
Two participant groups, defined as “rich” or “poor” according to a measure of household income, performed similarly on these cognitive tests when the amount of money in the spending scenario was small. But when a large financial outlay was required, cognitive performance dropped significantly for those in the poor group. By contrast, the performance of the “rich” was unaffected by the amount of money they had to consider spending.
This effect is not due to the complexity of the financial sums involved, because presenting similar problems in terms of abstract numbers rather than money did not affect measured intelligence. Rather, it seems that financially worrying scenarios capture attention and so causes the drop in cognitive performance.
Strikingly, an equivalent effect of money worries was found in the Indian farmers. In this experiment, the same farmers were tested twice in the year, just after the annual sugar-cane harvest – when they were relatively affluent – and just before the harvest, when money was tight. The effect of poverty on intelligence seemed to be independent of food scarcity, recent physical labour, biological measures of stress or specific anxiety associated with the harvest.
So, if you do not have enough money relative to your needs, this places a major strain on your cognitive resources, reducing your ability to make effective decisions. It is clear how this could lead to a self-reinforcing poverty trap, consistent with previous research showing, for example, that poor people are often worse managers of their own finances. Given this, an obvious question is whether we should change how society places financial demands on those who are least equipped to deal with them.
Michael Hyland writes:
It is interesting to find the link between poverty and intelligence. The link between poverty and health has been established for many years. However, is there a link between the poverty-intelligence relationship and the poverty-health relationship? I certainly think it possible. We have a paper in press which shows that that there is a biological latent variable (i.e., a ‘hidden’ variable discovered through factor analysis) that we called biological health or h. The concept of h parallels that of g or general intelligence. h is associated with increased inflammatory mechanisms. The question is, whether these inflammatory mechanisms then have an effect on cognition. It is certainly possible as we know that many of the pro-inflammatory cytokines have an effect on the brain associated with fatigue and depression. We have certainly speculated that this underlying inflammatory state – which is brought about by chronic stress – affects health, cognition and personality. So in this time of examinations, I repeat my message to students – don’t stress your immune systems!
Hyland, M. E., Jeffery, A. N., & Wilkin, T. J. (2014). A biological, latent variable model of health (EarlyBird 68). Brain, Behavior, and Immunity.