IB Psychology HLTopic 2 — Development of the SelfPaper 1 & 2Key study~10 min read
How Childhood Poverty Shapes Development
Poverty is not only about having less. For a developing child it changes the raw materials development runs on — food, safety, stimulation, stability — and it does that during the years when the brain is least able to wait.
📘 What you need to know
Poverty affects children more severely than adults, because development depends on consistent access to basic needs and stimulation.
Global Multidimensional Poverty Statistics (2022) put roughly 9.2% of the world’s population — about 700 million people — in extreme poverty, living on less than $1.90 a day. Around 26%, some 1.3 billion people, live in moderate poverty on $1.90 to $3.20 a day. At least 80% of the world lives on less than $10 a day.
Quote one figure, not all three. A single well-placed statistic looks confident; three in a row looks like list-learning.
What poverty does to development
Area
What is missing
Developmental effect
Health
Enough food, and food of decent quality and variety
Undernourishment or malnourishment, which affects growth and cognition
Education
Trips, hobbies, extracurricular activities, being read to
Fewer enriching experiences, so slower progress even at the same school
Wellbeing
Stimulation, stability, a calm home
Stress undermines both emotional security and cognitive development
Malnourished does not mean starving. A child eating plenty of cheap, heavily processed food can be malnourished — poor quality and low variety — without being undernourished. Kar’s study is about that difference.
Key study: Kar et al. (2008)
🧩 The study in four steps
Aim — to investigate the effect of poverty and malnutrition on children’s cognitive performance.
Participants — 40 children from Bangalore, India, aged 5–7 and 8–10 years. 20 were identified as adequately nourished and 20 as malnourished.
Procedure — a series of tests assessing neuropsychological functioning: motor speed (finger tapping), attention span (trailing two colours), executive functioning (naming items beginning with the same letter), visual-spatial ability (completing an object with a missing part), comprehension (understanding verbal commands) and memory (recalling abstract designs).
Findings and conclusion — the malnourished children performed worse on most tests, with the exception of motor speed, the least cognitively demanding measure. Impairments were significant on higher cognitive functions: attention, working memory and verbal comprehension. There were also delays in executive functions such as planning ahead, decision-making and impulse control. Their cognitive development may follow an altered or delayed trajectory.
The motor speed result is the interesting one. Because it was the least demanding test and showed almost no difference, the researchers could argue the problem lies in higher cognitive functions rather than general slowness.
That is a beautiful piece of study design to point out in an ERQ. Motor speed acts almost like an internal control: if the malnourished children had simply been tired or unmotivated, that test would have dropped too.
Evaluating this research
Strengths
Genuine usefulness. The findings can be used to argue for interventions that target malnutrition directly.
Policy relevance. Kar’s results could be used to persuade governments to fund breakfast clubs in schools and food banks, so that no child goes without adequate nutrition.
Method triangulation. Several different types of test measured a range of variables, which protects internal validity and reduces the risk of bias from relying on one measure.
Limitations
The problem is bigger than the research. Tackling poverty requires governments and agencies to work together, so knowing the effects does not produce a solution by itself.
Fatigue and distress. The malnourished children sat through a long battery of tests and may have experienced fatigue or distress. That is an ethical consideration whenever participants are vulnerable.
Small sample. 40 children from one Indian city cannot represent children in poverty everywhere.
Correlational. Malnutrition travels with many other disadvantages, so isolating nutrition as the cause is not possible here.
Link to concepts
Responsibility — this is a delicate, sensitive area. People living in poverty should not be portrayed as “poor”, “needy” or in any way inferior. Researchers must use reflexivity: asking what preconceptions they brought with them, what they assumed before the research began, and whether they are slipping into a “saviour” mode that produces a researcher effect.
Measurement — using several different tests is method triangulation, which strengthens internal validity by avoiding reliance on a single, possibly biased, measure.
Exam practice
WORKED EXAMPLE
Outline one effect of poverty on childhood development. [3 marks]
1. Name the effect
Poverty is linked to malnourishment, which affects cognitive development.
2. Explain the linkPoor quality, low variety diet deprives a developing brain of what it needs during key years.
3. Evidence
Kar et al. found malnourished children in Bangalore performed worse on attention, working memory and verbal comprehension, but not motor speed.
Effect + mechanism + evidenceThe “but not motor speed” clause shows genuine understanding. Keep it.
WORKED EXAMPLE
Discuss ethical considerations in research on poverty. [ERQ paragraph]
Issue
Participants in poverty research are vulnerable, and Kar’s malnourished children faced a long series of demanding tests.
ExplainFatigue and distress are real risks, and protection from harm has to outweigh the value of extra data.
Second issue
Researchers must avoid portraying participants as inferior or adopting a “saviour” stance, which distorts findings through the researcher effect.
Judgement
Reflexivity is not optional here — it is what keeps the research both ethical and valid.
Ethics and validity, same problemEthical points score far better when you tie them to validity.
💡 Exam tip
Distinguish undernourishment from malnourishment in one sentence. It is a quick, precise mark.
Use the Luby study from the neuroplasticity page as your second piece of evidence — it links poverty to brain volume and adds a protective factor.
Name at least two of Kar’s tests. Vague answers about “cognitive tests” score less.
Reflexivity and method triangulation are the two terms examiners want here.
Talk about breakfast clubs and food banks for the application point. Concrete beats abstract.
Write about people in poverty with respect. Careless phrasing genuinely costs marks in this topic.
⚠️ Common mix-up
“Poverty causes low intelligence.” Wrong and unsupportable. Say malnutrition is associated with impaired performance on certain tasks.
Motor speed did not drop much. Students often report all tests as worse and lose the most interesting finding.
40 children, not 40 families. 20 in each group.
Executive function is not memory. It is planning, decision-making and impulse control.
This is a quasi-experiment, not a true experiment. Nourishment status was pre-existing, not assigned.
Do not describe participants as “victims”. Describe the conditions, not the people.
Up next: Growing Up in a Conflict Zone — and a researcher who argues that the way we describe children in hard circumstances can itself do damage.
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