In the modern workplace, mental clarity, cognitive agility, and the ability to process information efficiently are vital to performance. But have you ever wondered how our brains have changed over time, and whether those changes have any impact on cognitive function today?
A recent study sheds light on the fact that human brains have actually grown larger over the decades. People born between the 1930s and 1970s show a 6.6% increase in brain size, with gains in key areas responsible for memory, information processing, and mental resilience. But does a bigger brain mean sharper intelligence or better performance? Let’s dive into the findings and their relevance to today’s workplace.
What Was Studied?
Researchers examined 3,226 adults with no significant neurological conditions, using MRI scans to analyse brain size (intracranial volume), white matter, gray matter, hippocampal volume, and cortical surface area. The participants were born between the 1930s and 1970s, and the results revealed some intriguing trends:
- White Matter Volume: Increased by 7.7%
- Hippocampal Volume: Grew by 5.7%, crucial since this part of the brain is tied to memory.
- Cortical Surface Area: Expanded by 14.9%, which relates to processing information.
- Cortical Thickness: Decreased by 20.9%, suggesting that while surface area increased, the cortex thinned over time.
The researchers attributed these changes to several societal shifts, including higher rates of education, improved nutrition, and a significant reduction in smoking rates.
Education, Nutrition, and Lifestyle: Key Drivers of Change
One of the most significant factors identified was educational attainment. As the population gained more access to education throughout the 20th century, brain volumes increased. Education has been shown to promote brain development during neurodevelopmental periods (such as childhood and young adulthood), which may explain why people born in more recent decades have larger brains.
Nutritional changes also played a role. With greater access to essential nutrients like iodine, vitamin B12, and protein, undernutrition rates have dropped significantly, allowing for healthier brain development. This aligns with the introduction of food fortification programmess, like adding iodine to salt and vitamins to bread, and access to food assistance programmes like school lunches.
Reduced smoking rates are another critical factor. Smoking has been linked to reductions in brain volume, particularly in gray matter, so the overall decline in tobacco use over the past few decades has likely contributed to brain growth.
Does a Bigger Brain Matter?
Here’s the catch: a bigger brain doesn’t necessarily mean a better brain when it comes to brain size and cognitive performance. While the study found an overall increase in brain volume, it’s important to note that brain size alone isn’t a reliable predictor of intelligence or mental sharpness.
For example, men tend to have larger brains than women—about 12% larger on average—but research shows no significant difference in cognitive performance between the sexes. Instead, cognitive function depends more on how well the brain is organized, its information processing speed, and neural communication. In short, a larger brain doesn’t automatically mean better intelligence or performance.
The Concept of Brain Reserve
One area where brain size might make a difference is in what’s known as brain reserve. This concept refers to having a larger supply of brain cells that can act as a buffer when the brain is damaged or begins to atrophy with age. A greater brain reserve may delay the onset of cognitive decline, including conditions like dementia.
Research supports the idea that people with higher brain reserve tend to have a lower risk of developing neurodegenerative diseases, such as Alzheimer’s. However, as with intelligence, brain size is only one piece of the puzzle. The functionality and efficiency of the brain matter just as much, if not more, than its overall size.
Implications for Cognitive Wellness in the Workplace
So, what does this mean for the workplace? The findings of this study highlight the importance of cognitive wellness. While brain size may not directly translate to better performance, maintaining brain health is essential for long-term mental sharpness and resilience, especially in high-performance environments.
As we know, the workplace of today demands not just physical stamina but also cognitive stamina—the ability to stay focused, process information quickly, and make critical decisions under pressure. By promoting cognitive wellness through initiatives that focus on mental agility, education, nutrition, and even stress management, employers can help employees optimise their mental performance and maintain it as they age.
What Can We Do to Support Cognitive Health?
Supporting cognitive health in the workplace involves a proactive approach to well-being. Here are a few strategies that can make a real difference:
- Encourage Lifelong Learning: Education isn’t just for school—it’s a tool for building cognitive reserve throughout life. Offer opportunities for continuous learning, upskilling, and intellectual engagement.
- Promote Healthy Lifestyles: Nutritional support, smoking cessation programmes, and access to wellness resources help employees take care of their brain health as much as their physical health.
- Focus on Mental Agility: Foster environments that challenge employees to think creatively, make decisions, and solve problems quickly, which strengthens cognitive resilience over time.
- Monitor Mental Wellness: Regular check-ins on mental wellness and stress levels can help prevent burnout and ensure employees are performing at their cognitive best.
The Big Picture
While the study provides valuable insights into how brain size has changed over time, it also reinforces a broader truth: brain health is multifaceted. It’s not just about size; it’s about how well the brain functions and how we can support it through education, nutrition, and lifestyle choices.
In a workplace context, investing in cognitive wellness ensures that employees not only perform at their best today but also build resilience for the future.
Important final note
This research was done in a single town in the USA so further research is required to extrapolate to other broader populations.
Citation - DeCarli C, Maillard P, Pase MP, Beiser AS, Kojis D, Satizabal CL, Himali JJ, Aparicio HJ, Fletcher E, Seshadri S Trends in Intracranial and Cerebral Volumes of Framingham Heart Study Participants Born 1930 to 1970. JAMA Neurol. (2024 May 1)