For much of the early 20th century, Neanderthal behaviour was depicted as primitive, unintelligent, and brutish; unevolved compared to their modern human contemporaries, the Cro-Magnons. Although knowledge and perception of Neanderthals has markedly changed since then in the scientific community, the image of the underdeveloped caveman archetype remains prevalent in popular culture.
Neanderthal technology achieved a degree of sophistication. It includes the Mousterian stone tool industry as well as the abilities to maintain and maybe create fire, build cave hearths, craft at least simple clothes similar to blankets and ponchos, make use of medicinal plants, treat severe injuries, store food, and use various cooking techniques such as roasting, boiling, and smoking.
Overall, Neanderthals maintained a low population and population density, and also mainly interacted with only nearby neighbours. Many groups suffered from inbreeding depression. Communities may have seasonally migrated between caves, but most of the raw materials Neanderthals used were collected within only 5 km (3.1 mi) of a site. Indicated by frequent evidence of stunted growth and traumatic injuries, Neanderthals lived harsh lives, which may be implicated in the 150,000 year stagnation in Neanderthal stone tool innovation.
Neanderthals consumed a wide array of food, mainly what was abundant in their immediate vicinity. This was normally hoofed mammals such as red deer and reindeer, but also megafauna, plants, small mammals, birds, and aquatic and marine resources. Although they were probably apex predators, they still competed with cave lions, cave hyenas, and other large predators. A number of examples of symbolic thought and Palaeolithic art have been inconclusively attributed to Neanderthals, namely possible ornaments made from bird claws and feathers, collections of unusual objects including crystals and fossils, and engravings. Some claims of religious beliefs have been made. The extent to which Neanderthals could produce speech and use language is debated.