IB Psychology SLTopic 2 — Development of the SelfPaper 1 & 2Key study~12 min read
How Childhood Poverty Shapes Development
Poverty is hard on anyone. It is hardest on children, and for a specific reason: development runs on a steady supply of food, safety and stimulation, and poverty interrupts all three at exactly the point when the supply matters most.
📘 What you need to know
Poverty affects a very large share of the world’s population, and children are over-represented among those affected.
Children are hit harder because development depends on consistent access to basic needs (clean water, food, shelter) and stimulation (books, play, adults who engage with them).
Growing up in poverty is a strong predictor of adult poverty, which is what creates a cycle of disadvantage.
Three areas of consequence: health, education and wellbeing.
Undernourishment means too little food. Malnourishment means a poor-quality or low-variety diet. They are not the same thing.
Key study: Kar et al. (2008) compared adequately nourished and malnourished children in Bangalore on a battery of cognitive tests.
Malnourishment was linked to the biggest problems in higher cognitive functions, not in simple ones.
The scale of it
The dollar figures here are the international poverty lines used in the 2022 statistics. Those thresholds get revised upwards every few years, so quote whichever figures your own course materials use — the pattern is what matters, not the exact cut-off.
Why children are hit harder than adults
An adult in poverty is having a very hard time. A child in poverty is having a very hard time while being built. Development depends on a steady input, and it does not pause and wait.
Basic needs
Clean water, enough good food, and shelter that is safe and stable. Missing these does physical damage during the years when the body and brain are growing fastest.
Stimulation
Books, toys, trips, conversation, an adult with the time and energy to engage. Missing these removes the raw material that cognitive development runs on.
The cycle
Poverty in childhood → poorer health, education and wellbeing → fewer opportunities as an adult → poverty in adulthood → the next generation starts in the same place.
The three consequences to learn
Health. Poor nutrition leads to undernourishment (not enough food) or malnourishment (a low-quality, low-variety diet). Both harm growth and cognitive development.
Education. Children may miss out on the enriching experiences that make school easier — trips, hobbies, extracurricular activities, being read to at home.
Wellbeing. Lack of stimulation, instability and constant stress undermine both emotional security and thinking skills.
Connect this to what you already know. Chronic stress affects the hippocampus and amygdala, and the caregiving finding from Luby et al. showed the effect can be softened. Poverty is not a separate topic from brain development — it is the same story told from the outside.
The key study
KEY STUDY
Kar et al. (2008) — malnutrition and cognitive performance
Aim
To investigate the effect of poverty and malnutrition on children’s cognitive performance.
Sample
40 children from Bangalore, India, in two age bands (5 to 7 and 8 to 10). 20 were identified as adequately nourished and 20 as malnourished.
Method
A series of neuropsychological tests, each targeting a different ability.
Motor speed — a finger-tapping test.
Attention span — following and trailing two colours.
Executive functioning — naming items beginning with the same letter.
Visual-spatial ability — completing an object with a missing part.
Comprehension — understanding spoken commands.
Memory — recalling abstract designs.
Findings
Malnourished children did worse on most tests. The exception was motor speed, the least cognitively demanding measure, where the groups were similar. The clearest impairments were in attention, working memory and verbal comprehension, and the malnourished group also showed delays in executive functions such as planning ahead, decision-making and impulse control.
Conclusion
Malnourished children experience cognitive impairments and developmental delays, and their cognitive development may follow an altered or delayed path.
Notice how this maps onto brain maturation. The abilities that suffer most are the ones handled by the slowest-developing parts of the brain.
Evaluating the research
Strengths
Limitations
Genuinely useful. The findings support interventions such as school breakfast clubs and food banks.
Correlational. Nutrition was measured, not assigned, so causation cannot be established.
Method triangulation. Several different tests measured different variables, which protects internal validity and reduces bias from any single measure.
Confounding variables. Malnourished children are also more likely to face illness, missed schooling and family stress.
A revealing pattern, not just a blanket difference — the exception for motor speed makes the result more informative.
Fatigue and distress. A long battery of tests is demanding, and the children were already a vulnerable group.
Standardised tests make the study replicable.
Small sample. 40 children from one city limits how far the findings can be generalised.
Link to concepts
Responsibility: researching poverty is delicate. People living in poverty should not be portrayed as needy or inferior. Researchers must use reflexivity — checking their own assumptions before, during and after the study — and resist slipping into a “saviour” role that distorts the findings.
Measurement: using six different tests is method triangulation. It gives a fuller picture than one measure and reduces the risk that a single flawed test drives the conclusion.
Change: tackling poverty needs governments and agencies working together, so psychological findings on their own can only inform the argument, not solve it.
Exam practice
EXAM QUESTION
Discuss the effects of poverty on childhood development. [22]
Poverty questions reward breadth. Cover more than one type of effect, then narrow onto one study for the detail.
Frame it
Children are more affected than adults because development depends on continuous basic needs and stimulation.
Cover the three areashealth → education → wellbeing, with the cycle of disadvantage joining them up.
Go deep on one study
Kar et al. (2008): 40 children in Bangalore, six neuropsychological tests, motor speed spared but attention, memory and executive functions impaired.
Evaluate the study
Triangulation and usefulness, against correlational design, confounds and a small sample.
Bring in a second study
Luby et al. adds the biological mechanism and the caregiving protective factor.
Judgement: strong evidence of harm, weaker evidence about which part of poverty does itthe caregiving finding stops the essay sounding hopeless, which examiners notice
💡 Exam tips
Distinguish undernourishment and malnourishment early. It is a quick precision mark.
Quote the motor speed exception. It shows you understood the finding rather than memorising “they did worse”.
Use the term method triangulation when evaluating Kar et al.
Pair this study with Luby et al. if you have space — one gives behaviour, the other gives biology.
Write about people in poverty respectfully. Careless wording reads badly and can cost you.
Say cycle of disadvantage rather than “poor people stay poor”. It is the accurate term.
⚠ Common mix-ups
Saying poverty causes low intelligence. The evidence shows a link with performance on tests, in correlational designs.
Confusing undernourishment with malnourishment. One is too little food; the other is poor-quality food.
Claiming all abilities were equally affected. Motor speed was largely spared.
Ignoring stimulation. Poverty is not only about food — missing books, play and adult attention matters too.
Treating poverty as one variable. It arrives bundled with stress, illness, instability and disrupted schooling.
Forgetting protective factors. Caregiving quality changes outcomes, so poverty is a risk, not a guarantee.
Up next: Growing Up in a Conflict Zone — and a study that turns the usual assumption on its head by asking whether calling children helpless is itself part of the problem.
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