Psychology in the News

This semester, I've been taking a developmental psychology course. One of the things that my professor takes very seriously is translating very jargon-y, complicated studies to a more digestible format to reach the wider public who may not have the field knowledge.

The article that I did mine on was a very interesting one on cognitive abilities and socioeconomic status. I thought I'd share it here!

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Socioeconomic Status Can Impact Multiple Cognitive Domains, Even for Children

But some are affected more than others.

Lower socioeconomic status (SES) can impact lifestyle, access to resources, and health outcomes. While it might be more straightforward to describe low SES as being ‘poor,’ the nuances may not be adequately presented, which is why studies like these choose to discuss SES. Previous research has already established the effect that SES has on cognitive abilities and achievement in childhood with measures like IQ. 

However, not much is known about the connection between SES and specific brain systems and how these functions develop. To answer this question, in the year 2005, researchers Kimberly G. Noble, M. Frank Norman, and Marth J. Farah of the University of Pennsylvania Center for Cognitive Neuroscience delved into the study that looked at five different domains of cognitive function performances in children. 

Who’s Involved?

This study's participants were thirty ‘middle SES’ and thirty ‘low SES’ African American kindergarteners recruited from the classrooms of Philadelphia’s public kindergartens. Children with health problems or developmental delays were excluded as it may present unexpected variations to the result. To meet the standard for the ‘low SES’ group, the highest level of education of an adult in the household could not exceed high school, and the income-to-needs ratio needed to be just above the poverty level. On the other hand, to qualify as a ‘middle SES’, at least one adult in the household had to have at least two years of college education, and the income-to-needs ratio would be greater than 1.5 (with no upper limit). 

What Was Done?

A series of tasks were designed to test the five broad brain functions: a) visual cognition, b) spatial cognition, c) memory, d) language, and e) executive function. The visual system was tested through tasks like the ‘shape detection task’ that got children to recognize and interpret visual stimuli. Tasks like the ‘mental rotation task’ assessed how children perceived spatial relationships by showing children a picture of candy canes from different perspectives and asking where the hooks of the candy cane would be. 

Memory tasks focused on the ability to recall and recognize objects and faces, while the language system was evaluated through vocabulary knowledge, understanding of sentence structures, and awareness of phonetics. Finally, the executive function tasks tested abilities like planning, inhibiting impulses, and working memory with tasks like the ‘Go/No-Go task,’ where children were asked to press a button for every animal except when they saw a cat. By breaking down cognitive performances into different domains, the study was able to provide a nuanced view of how SES might affect specific areas of brain development. 

The study also collected data via a questionnaire for parents, recording the number of hours per week a child had spent in preschool/daycare before kindergarten and the frequency with which they engaged in pro-academic activities like reading at home or talking about what the child has learned in the school day. This would provide a well-rounded understanding of the children’s access to a learning environment. 

What Did They Find?

The most prominent finding was that lower SES had a negative impact on language and executive function. Children from lower-SES backgrounds consistently performed worse on tasks related to these areas compared to their middle-SES peers. Children from the middle-SES group scored higher in tasks of measuring vocabulary knowledge. Similarly, in executive function tasks, which involved higher-order thinking skills like self-control and problem-solving, lower SES children showed shortcomings. Skills critical for academic and everyday achievements, such as remembering sequences or restraining oneself when necessary, were impeded for the lower SES group. 

While the study found that SES is strongly linked to disparities in language and executive function, it didn’t find significant differences in other domains like memory, visual function, and spatial function. This suggests that certain brain systems are more sensitive to the effects of SES-related factors, such as access to language-rich environments and opportunities for developing executive control. 

So, What Does This All Mean?

Is all hope lost for children growing up in lower SES environments? As with most developmental research into performance gaps, the disparities in language and executive functioning in children of lower SES can be overcome by educational interventions, such as intensive early education (Ramey & Ramey, 1998). The results of this study also imply a practical step in similar research fields: researchers must consider SES differences when investigating the foundational development of language and executive functions. 

Future studies may examine how other variables, like genetics, could also affect cognitive development. The study’s measures, for the most part at least, were meticulously laid out, using detailed assessments of specific cognitive systems rather than broader measures like IQ. This approach has allowed for a more precise understanding of how SES influences brain development. 

What is also interesting about this study is that all the participants were of the same ethnicity (African-American). This was a conscious choice on the part of the researchers to ensure that the reasoning behind the results of varying degrees of skills would not be reduced to innate racial abilities. Instead, the differences could be attributed to what the study was actually about: varied SES levels. 

The researchers recognized that the study had a relatively small sample size, and SES was only measured in two categories, meaning the interpretations of the results may not have fully accounted for individual differences or the subtle distinction of a more finely defined ‘SES level’. Noble and her colleagues reckon that causal relationships between SES and differences in language/executive function abilities could be addressed through intervention programs that target these areas. The team offered a look at a prospective study where two groups would be randomly assigned to separate interventions; this could make clear the causal factors relating to differences in cognitive outcomes.  

The Take-Home Message

Environment and experiences associated with different SES levels seem to play a crucial role in developing certain cognitive abilities over others. While not every child will have the same starting line, policymakers, stakeholders, and educators should strive to create a more equitable opportunity for academic success by identifying areas of intervention that can help mitigate these obstacles.

Fascinating, right? If you do want to read the actual study, you can find it here.