The Neolithic Revolution involved the transition of early humans from hunter-gatherers to farmers around 8,000 BCE. During this time, permanent settlements like Catal Huyuk emerged and social hierarchies developed with women taking on domestic roles. Jared Diamond believed the Neolithic Revolution was a mistake as it led to increased disease, smaller human stature, and less leisure time while creating rigid social classes. Characteristics of early civilizations included job specialization, record keeping, cities, technology, art/architecture, and organized religion like Stonehenge. Social scientists who study pre-history and early civilizations include archaeologists, historians, geographers, anthropologists, and sociologists. The Paleolithic Age or Old Stone Age occurred