Neanderthals had powerful thumbs, while humans had more precise control

A 3D analysis of the joints between the bones responsible for thumb motion belonging to Neanderthals revealed how our extinct cousin may have grasped objects. According to the analysis, Neanderthal thumbs were better suited to power take-offs, the kind seen when holding a hammer. However, this made it more difficult to employ precision grip, which may have given humans the upper hand during times when the two species of Homo they were in direct competition for resources.

Neanderthals could have wielded a spear better than early humans, but were lacking in other departments

Modern archaeological finds show that Neanderthals were not brutes that many imagined they were. They fashioned necklaces and other types of jewelry and were just as elaborate and creative with their cave paintings as the humans of the time. They have made bids for flower burial, which indicates a complex cultural heritage, as well as mastered fiber technology and likely grasped basic math judging by the pattern of the thread and ropes.

Either way, Neanderthals and humans were much more alike than they were different. In fact, they have crossed paths numerous times, a fact attested to today by 2% of our DNA which is of Neanderthal origin.

But, eventually, the Neanderthals went extinct some 40,000 years ago, as humans continued to dominate the planet’s ecosystems, spreading to all seven continents. So while Neanderthals were also intelligent and resourceful, humans may have had an added advantage in other areas.

Perhaps Neanderthals were more vulnerable to diseases that humans themselves could have brought with them from Africa and the Middle East. A new study published today in the journal Scientific reports could point to a different conclusion: Neanderthals may have been technologically overwhelmed not because of their inferior ingenuity, but rather because of their working hands which were less adapted to precision grips.

Researchers led by Ameline Bardo of the University of Kent in the UK mapped the joints between the bones responsible for thumb movement – collectively known as the trapeziometacarpal complex – in five Neanderthals. The 3D digital models were compared with those of measurements of the same joints belonging to five early modern humans, the first of whom lived about 95,000 years ago in present-day Israel. The comparative analysis also involved the thumb joints of 50 recently deceased modern human adults.

In Neanderthals, the joint connecting the wrist bone at the base of the thumb with the first thumb bone connecting the wrist was best suited for extension along the side of the hand. This thumb posture is more suited to power squeeze holds, the kind we would use to hold a hammer. The powerful grip must have come in handy for the Neanderthals when they grabbed the spears used for hunting.

In contrast, modern humans have thumb joints that are generally larger and more curved than those seen in our extinct cousins. This configuration is best suited for grasping objects between the finger and thumb pads, such as holding a pen.

Ultimately, this precision grip may have helped humans develop better technologies. However, there is currently no way of knowing how skilled the Neanderthals were. After all, there are many variations in the dexterity of humans and there is no reason to believe why Neanderthals were any different. Perhaps a larger sample size would clear things up a bit.

“The results show a distinct pattern of shape covariation in Neanderthals, consistent with more extended and adducted thumb postures that may reflect the habitual use of commonly used grips for handled instruments,” the study authors wrote.

“These findings underscore the importance of holistic joint shape analysis for understanding the functional capabilities and evolution of the modern human thumb,” they added.