LONDON, Nov. 4 (UPI) -- Stone Age humans developed relatively advanced tools only after their brains evolved a greater capacity for complex thought, U.K. researchers say.
A study led by researchers at Imperial College London reveals why it took almost 2 million years for humans to progress from using sharpened stones to creating and using hand-held stone axes, ScienceDaily.com reported Thursday.
Comparing the manufacturing techniques used for each type of tool provides evidence of how the human brain and human behavior evolved and advanced during the Lower Paleolithic period, researchers say.
"The advance from crude stone tools to elegant hand-held axes was a massive technological leap for our early human ancestors," says neuroscientist Aldo Faisal from the departments of bioengineering and computing at Imperial College.
"Hand-held axes were a more useful tool for defense, hunting and routine work.
"Interestingly, our study reinforces the idea that tool making and language evolved together as both required more complex thought," Faisal says.