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the size of your kid's brain may be tied to how much you make

research shows a lower annual household income means lower scores on memory and vocabulary tests.

by emma jones

aug 13 2020

3 minute read

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family income may impact brain development in children

food security, access to educational support, and stress are factors that may impact the brain development of children inna reznik / istock / getty images plus

university of toronto researchers have released a study potentially demonstrating the effects that socioeconomic status in childhood has on specific regions of the brain.

the study, published in the journal nature on wednesday, found that children from wealthier families have a larger anterior hippocampus, a region of the brain associated with perception and memory. this finding adds a physical element to previous studies that suggest children from low-income households are more likely to struggle with developing memory and language abilities than wealthier peers.

“what we found — and what makes this result novel — is that it’s the anterior hippocampus that is associated with differences in cognition related to income,” alexandra decker, the lead author and phd candidate said in a statement .

researchers looked at an existing dataset of brain scans of 703 children, between 3 and 21, and compared this information with assessments of memory, vocabulary, and reported family income.

effects of low income

overall, researchers found that scores on memory and vocabulary tests, as well as volume of the anterior hippocampus, correlate with household income up to approximately $75,000 annually. in other words, the smaller the annual household income, the lower children tended to score on memory and vocabulary tests and the lower the volume of the front region of the hippocampus. (increased income past the $75,000 threshold do not seem have a significant benefit to the volume of this region of the brain or memory and vocabulary skills).

other potential factors that are known to effect brain function include access to fresh, healthy food (food security), tutors and other educational support. research has also shown that families with higher socioeconomic status tend to spend more time on reading activities — key in the development of vocabulary and basic academic skills.

“parents from families with higher incomes are more able to take time off work and are less likely to be working multiple jobs,” said decker. “they’re also generally able to consistently afford enrolment in enriching programs and nutritious meals.”

although previous research has connected stress to altered functioning of neurons in the hippocampus and a decrease in volume in this brain region, the dataset used by the researchers did not have a measure of stress. because of this, the results of the study cannot solely point to the stress associated with low income, such as living with parents who are anxious about paying bills or affording groceries.

the study also found that these effects were not moderated or exacerbated by ethnic background, making these results generalizable to most children who live in a household with less than a $75,000 annual income. however, the researchers noted there were few individuals of minority backgrounds in the high income range, making it difficult to understand if any differences exist with wealthier families.

the research also did not take into account children being raised in rural versus urban environments or differences in regional cost of living. as this sample set was collected in ten regions throughout the united states, it stands to reason that the majority of the sample set resides primarily in the u.s. thus, other potentially mitigating factors such as universal access to healthcare are not clear.

understanding different regions of the hippocampus

this paper also took the unusual step of evaluating different areas of the hippocampus individually. typically, research looks at the hippocampus as one homogenous structure, possibly conflating the results of various life experiences on this part of the brain.

“these regions develop differently and play different roles in cognition — and they have different sensitivities to stress,” said decker.

by separating their analysis of the hippocampus into the front (anterior) and back (posterior) regions, the team was able to tease out the nuanced effects that stress and other factors can have on various regions of the brain. while the front region of the hippocampus was effected by changes in household wealth – the back region was not. this may explain why a physical basis for the wealth effects on memory were elusive until now.

thanks to this more specific understanding on the way the brain functions, researchers now have better targets for intervention and a better understanding of the cognitive processes that low income children need to flourish.

emjones@postmedia.com | @jonesyjourn

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the size of your kid's brain may be tied to how much you make

research shows a lower annual household income means lower scores on memory and vocabulary tests.

effects of low income

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understanding different regions of the hippocampus

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