According to some researchers, our brains may have shrunk by 17.4% in the course of the last 20,000 years. But this alleged shrinkage can not be blamed because there is evidence showing that this process was ongoing even before the advent of the modern-day technologies. But a shrinking in size may not correlate to our intelligence.
According to Michel A Hofman who is a professor of neurobiology at the Netherlands Institute for Neuroscience, fossil records have indicated that our brains have been getting smaller over the course of the last 10,000 to 20,000 years. This is a clear indication that this alleged decrease in the size of our brains is not caused due to the coming of smartphone and other modern-day gadgets.
But contradicting his own statement somewhat, Dr Hofman has also said that there has been no scientific evidence that the modern human brain has been getting smaller in size in the last few centuries at least. He goes on to say that many researches out there suggest that data are based on highly inaccurate and untrustworthy data.
This confusion regarding this phenomenon arises because researchers do not have access to any old brains which they could look at and examine. They can only make best guesses and estimates based on endocranial casts, models made of the inside of old skulls. These casts give researchers an idea about brain size, shape, and surface of the brain and how it has change over the years.
Even without concrete proof to substantiate the claim, it is a worrying trend to think about because shrinking grey matter over the generations does not sound all that appealing.
But all news is not bleak, according to Dr Hofman, a shrinking brain does not necessarily mean that we are less intelligent than our ancestors.
As stated by Anna Henschel MSc, a final year PhD candidate at the University of Glasgow’s Social Brain In Action Laboratory, the relationship between brain size and intelligence is very weak and sketchy at best. Examples of this can be seen from the animal kingdom as well, because if bigger brains meant greater intelligence then whales and elephants would be a lot smarter than humans. But this is not the case at all.
While the answer is no definitive for now at least, some researchers claim that our brains are shrinking because of a change in the climate, but there may be many more reasons such as diet, lifestyle and food availability that could be contributing to it.