Final answer:
The formal study of Neandertals began after remains were found in Neander Valley, Germany, in 1856. This marked the beginning of systematic scientific research into Neandertals, who are now known to have had a rich culture and cognitive abilities reflected in cave art and evidence of complex behaviors.
Step-by-step explanation:
The first evidence of Neandertals was indeed found in Engis Cave, Belgium, in 1829; however, it was not until the discovery of Neandertal remains in the Neander Valley, Germany, in 1856 that more rigorous scientific study began. The remains in the Neander Valley were identified as belonging to an extinct type of human and were thus named after the location of their discovery - Neanderthals. This undertaking marked the beginning of the formal study and recognition of Neandertals as a distinct group.
Research is ongoing to understand the complexities of Neandertal life, their capacities for culture, and their interactions with early modern humans. Significant findings like the Shanidar Cave in Iraq, which revealed evidence of traumatic injuries and potential hunting activities by Neandertals, or the cave paintings in Spain dated to around 65,000 years ago, suggest Neandertals had cognitive abilities and participated in the creation of cave art, challenging earlier assumptions about their capabilities.