A brain scientist from the Los Angeles Natural History Museum JM Stibel says that our brain size has decreased in the last 50,000 years. Stibel is the author of the study, published in the journal Brain, Behavior and Evolution.
His research reveals that brain size has been reduced by more than 5 percent in modern homosapiens.
Stibel also found evidence that brain size relative to our body (known as encephalization) has also decreased…mainly due to obesity. Apart from obesity, other factors like health, education, and technology might also have contributed to brain size shrinkage.
Stibel also points out that “a significant decrease in IQ has been noted over the past 30 years in many parts of the globe, with the largest declines occurring across industrialized nations.”
It’s worth noting that Stibel used IQ as a measure of intelligence. Although this benchmark is widely accepted as a standard benchmark to assess cognitive function. It is still not considered to represent a comprehensive measure of intelligence.
We conventionally associate big brains with intelligence. But there is no simple relationship between brain size and intelligence.