Title: Has the Human Brain Grown Larger by 6.6% Over 40 Years? Does a Larger Head Really Mean Greater Intelligence?
The debate over whether a larger brain equates to higher intelligence has been ongoing for centuries. Now, a new study suggests that the human brain has increased in size by 6.6% over the past 40 years. But does this mean we are evolving to become more intelligent?
According to a study published in the academic journal ‘JAMA Neurology,’ researchers at the University of California, Davis, have found that the human brain has been gradually increasing in size. The study analyzed brain magnetic resonance imaging (MRI) data from over 3,000 participants born between the 1930s and 1970s. The researchers discovered that the average brain volume of those born in the 1970s was 6.6% larger than those born in the 1930s. Additionally, the average surface area of the brain increased by 2.3% over the same period.
The study, which used data from the Framingham Heart Study (FHS) that has been ongoing since 1948, suggests that this increase in brain size might be associated with a greater brain reserve, potentially reducing the overall risk of age-related dementias such as Alzheimer’s disease.
However, the question remains: does a larger brain necessarily mean greater intelligence?
The idea that brain size is directly proportional to intelligence dates back to the 19th century when German anatomist and physiologist Friedrich Tiedemann posited that there was a close relationship between the absolute size of the brain and intellectual function. Since then, the topic has been a subject of intense debate, with hundreds of studies conducted to explore the correlation.
While scientists now widely acknowledge a moderate correlation between brain volume and intelligence (with a correlation coefficient r of approximately 0.30-0.40), it is not an absolute measure. From the data, it is indeed true that the brain has become larger, but the limitations of the study lie in the relatively small sample size, making it difficult to draw significant conclusions, said Dr. Chen Lihan, Associate Professor at the Department of Psychology and Cognitive Science at Peking University, in an interview with Sohu Technology.
Dr. Chen pointed out that the function and network patterns of the brain are more important than its physical size in determining a person’s intelligence. Brain function directly influences our thinking, memory, learning, emotions, and behavioral responses. The development and refinement of different brain regions, such as the prefrontal and parietal lobes in cognitive activities, and the hippocampus in memory, are crucial for cognitive processing and problem-solving abilities.
Moreover, the network patterns of the brain, involving the connections and communication between different brain regions, play a central role in information transmission and processing. An efficient brain network pattern can process information more quickly, making us more rapid, accurate, and flexible in thinking and decision-making.
The human brain is also plastic, meaning that its functions and network patterns can be modified and optimized through learning and experience. This suggests that even if a person’s brain size is not ideal, their cognitive performance can still be improved through continuous learning and practice.
The study also raises questions about why the human brain is so large. Some theories suggest that the increase in brain size is related to ecological intelligence theory, which posits that the brain’s growth is linked to survival. In ancient times, humans had to think hard to find food and avoid becoming prey, which led to an increase in brain size. Another theory is the social intelligence theory, which suggests that in today’s diverse and fast-paced world, humans need to maintain social connections and think strategically to cooperate and compete, which also contributes to brain growth.
Genetic selection and evolution are also key factors, as the number of neural stem cells in the cerebral cortex has increased, and the time it takes to produce neurons has lengthened, eventually leading to the evolution of the human brain with advanced functions.
In conclusion, while the human brain has indeed grown larger over the past 40 years, it is not a straightforward indicator of increased intelligence. Intelligence is a complex trait influenced by various factors, including brain function, network patterns, and genetic and environmental factors. The study provides valuable insights into the evolution of the human brain but also highlights the need for further research to understand the intricate relationship between brain size and intelligence.
Views: 0