The misconception of Neanderthals as stooped, brutish, hairy and dumb comes primarily from our preconceived notions. Indeed, even the first skeletal reconstruction of a Neanderthal, which was hunched and bent at the knees, turned out to be the result of French paleontologist Macellin Boule using bones from an old male Neanderthal with severe arthritis blended with Boule's expectation that Neanderthals were more apelike than human-like.

Even though we now know the errors in thinking that went into that first reconstruction, it still went a long way toward setting the stage for our "primitive" cousin. However, it turns out that Neanderthals were smart, strong, capable cousins who were far more like humans than you might suspect.

We know this because of several facts that have come to light in recent decades, and these discoveries are changing the old but persistent falsehood that Neanderthals were our dumb, lesser cousins. Turns out they were the equals of modern humans in many ways. Here are a few things you might not know.

Neanderthals buried their dead and left grave markers

Studying around 20 grave sites in western Europe, researchers have concluded that Neanderthals sometimes buried their dead. This might seem minor at first glance, considering how seriously we humans take ceremonies and funeral rites for the dead. Indeed, that tradition has long been considered something only modern humans do. However, Neanderthals also practiced the act of purposefully burying their dead, perhaps before contact with modern humans.

Not only did they sometimes bury their dead, but they may also have left flowers and other grave markers with their deceased.

Smithsonian reports:

From pollen found in one of the Shanidar graves, [Smithsonian anthropologist Ralph] Solecki hypothesized that flowers had been buried with the Neanderthal dead — until then, such burials had been associated only with Cro-Magnons, the earliest known H. sapiens in Europe. “Someone in the last Ice Age,” Solecki wrote, “must have ranged the mountainside in the mournful task of collecting flowers for the dead.” Furthermore, Solecki continued, “It seems logical to us today that pretty things like flowers should be placed with the cherished dead, but to find flowers in a Neanderthal burial that took place about 60,000 years ago is another matter.”

The symbolic gesture of leaving flowers with the dead is in line with other behavior that reflects symbolic thinking by Neanderthals, including decorating themselves with pigment and jewelry of feathers and shells. No other primate and no other earlier human species practiced burying their dead.

"It is novel evidence that Neanderthals were able to develop, by themselves, some complex symbolic thought," William Rendu, a paleoanthropologist at France's National Center for Scientific Research and New York University told LiveScience. "The behavioral distance between Neanderthals and anatomically modern humans seems to become even thinner."

Neanderthals were perfectly capable of using fire

Evidence from Neanderthal tools and living sites show they had controlled the use of fire. Evidence from Neanderthal tools and living sites show they had controlled the use of fire. (Photo: Alexandr Shevchenko/Shutterstock)

The controlled use of fire is one skill that sets humans apart from all other species. However, there was a time when we weren't the only species that regularly started and used fires. Neanderthals were skilled at this as well, as a 2011 study out of University of Colorado, Boulder, showed.

The researchers looked at 141 fireplace sites in Europe and noted the kind of evidence of sustained use of fire at each site, including burned bones, heated stone artifacts and charcoal. Their conclusion is that Neanderthals had sustained use of fire starting as far back as 400,000 years ago.

Not only did Neanderthals use fire to cook food, but they also used it to make needed materials.

According to CU Boulder Today:

According to Villa, one of the most spectacular uses of fire by Neanderthals was in the production of a sticky liquid called pitch from the bark of birch trees that was used by Neanderthals to haft, or fit wooden shafts on, stone tools. Since the only way to create pitch from the trees is to burn bark peels in the absence of air, archaeologists surmise Neanderthals dug holes in the ground, inserted birch bark peels, lit them and covered the hole tightly with stones to block incoming air.

"This means Neanderthals were not only able to use naturally occurring adhesive gums as part of their daily lives, they were actually able to manufacture their own," Villa said. "For those who say Neanderthals did not have elevated mental capacities, I think this is good evidence to the contrary."

Neanderthals were extremely skilled hunters

Neanderthals were not reliant on gathering for their sustenance, but proved themselves to be exceptional hunters with a deep knowledge of the skills needed to capture different types of game as well as strong communication skills to coordinate attacks.

Dutch researcher Gerrit Dusseldorp notes that even the most difficult-to-catch game, including herding animals that are tough to surprise or large, powerful animals, were all on the Neanderthal menu. Science Daily, commenting about Dusseldorp's research, said: "That the Neandertals were capable of hunting down such elusive game demonstrates that they had good coordination skills and could communicate well with each other... Dusseldorp demonstrated that Neandertals, thanks to their intelligence, even surpassed hyenas at capturing the strongest game."

In 2011, research showed that Neanderthals were aware of migration patterns of reindeer and timed their stays in certain hunting locations based on the movement of their prey.

In terms of strength, Neanderthals were not to be trifled with. Smithsonian notes, "Neanderthal bones have a high frequency of fractures, which (along with their distribution) are similar to injuries among professional rodeo riders who regularly interact with large, dangerous animals."

Humans didn't wait long to breed with Neanderthals

While it's known that modern humans mated with Neanderthals, recent research shows the interbreeding happened far earlier and more often than we previously thought. As far back as 100,000 years ago, modern humans moving out of Africa encountered and mated with Neanderthals.

Science magazine reports:

After early modern humans emerged in Africa about 200,000 years ago, some eventually left the continent and mixed with Neandertals in the Middle East or the Arabian Peninsula, where fossils and stone tools of both groups date back to about 120,000 to 125,000 years. This group of modern humans went extinct, but their DNA persisted in the Neandertals that headed east to eventually settle in Siberia. Meanwhile, another group of modern humans left Africa much later and interbred 50,000 to 60,000 years ago with Neandertals that had headed south from Europe to the Middle East. In this later migration, Neandertals interbred with the ancestors of living Europeans and Asians, who then spread throughout Eurasia. Some of this group of modern humans also encountered Denisovans, picking up the DNA that persists today in Melanesians and some Asians.

What isn't yet known is how the encounters happened — were they peaceful meetings, or were they raids in which one group stole the females of another group?

"Eventually, geneticists should be able to show if the transfer of DNA in either direction was mainly via males, females, or about equal in proportion, but it will need a lot more data before that becomes possible," Chris Stringer, a professor and research leader in human origins at the Natural History Museum in London, told BBC.

The documentary below explores how our study of the DNA clues of Neanderthals is changing the way we understand our ancient cousins.

Mating with Neanderthals was bad for our health

While the genetic diversity that came from these encounters may have ensured that the humans who left Africa survived to modern times, it came at a price. It turns out that many modern day genetic illnesses likely came from the Neanderthal side of the family.

A study looking at pieces of the DNA in modern humans that trace back to Neanderthals shows this inheritance includes a higher risk of blood clots and strokes, depression, skin lesions, a propensity for nicotine addiction and even malnutrition due to imbalanced thiamine.

"Ultimately, the researchers found that Neanderthal genetic variants were significantly linked to increased risk of 12 traits, including heart attack and artery thickening," states LiveScience.

These traits are related to adaptations that would have been beneficial in prehistoric times when our bodies were regulated by circadian rhythms, a very different diet and the need for boosted immune systems. But in today's modern world, the once beneficial traits are now problematic.

Science magazine notes, "But however beneficial in the Pleistocene and to people living in poor conditions today, even immune-boosting genes may have deleterious effects in the United States and Europe, where people face fewer parasites: [computational biologist Janet] Kelso found that the archaic receptor genes were strongly linked to allergies."

Neanderthals looked after sick and elderly family members

It may be easy to assume that for tough-living Neanderthals, it would be an everyone-for-themselves mentality. But Neanderthals were loving family members, caring for the injured, sick and elderly.

A burial pit at La Chapelle-aux-Saints in France, first found in 1908, revealed the bones of an elderly man who had no teeth and had debilitating arthritis, showing that this family cared for him into his later years, perhaps even chewing his food for him. Evidence found from bones in other sites repeat the story that fellow members of a group of Neanderthals must have cared for individuals who suffered debilitating injuries.

Smithsonian notes one example of a skeleton found by archaeologist Ralph Solecki in the 1950s of a male Neanderthal who died at the age of about 40 or 45:

A blow to the left side of his head had crushed an eye socket and almost certainly blinded him. The bones of his right shoulder and upper arm appeared shriveled, most likely the result of a trauma that led to the amputation of his right forearm. His right foot and lower right leg had also been broken while he was alive. Abnormal wear in his right knee, ankle and foot shows that he suffered from injury-induced arthritis that would have made walking painful, if not impossible. Researchers don’t know how he was injured but believe that he could not have survived long without a hand from his fellow man.

So not only were Neanderthals crafty at making tools, quick to adapt to harsh conditions, and clever and strong hunters, they also cared for those within their family group to the point that a member could live for (perhaps) many years after a major injury. The more we study the evidence of Neanderthal life, the more we discover their softer side.

Neanderthals had loud, high-pitched voices

Nope, they didn't go around grunting. While they might not have had particularly sophisticated vocabularies, Neanderthals were capable of complex speech thanks to the presence and position of the hyoid bone, a bone structure located in the neck that supports the root of the tongue. This is the very bone that allows modern humans to vocalize as we do.

A team of researchers modeled how the bone worked within the throat of Neanderthals. BBC reports:

Stephen Wroe, from the University of New England, Armidale, NSW, Australia, said: "We would argue that this is a very significant step forward. It shows that the Kebara 2 hyoid doesn't just look like those of modern humans — it was used in a very similar way." He told BBC News that it not only changed our understanding of Neanderthals, but also of ourselves. "Many would argue that our capacity for speech and language is among the most fundamental of characteristics that make us human. If Neanderthals also had language then they were truly human, too."

While they could speak like us, they didn't necessarily sound like us. Their build likely gave them a higher-pitched and quite a loud voice. In this video, vocal experts explain how their large chests and posture likely made Neanderthals sound:

Jaymi Heimbuch ( @jaymiheimbuch ) focuses on wildlife conservation and animal news from her home base in San Francisco.