William F. Ogburn, an influential American sociologist, introduced the concept of 'cultural lag' in his 1922 work, 'Social Change with Respect to Culture and Original Nature.' Cultural lag describes a situation where one aspect of culture changes more rapidly than another, leading to a period of maladjustment or tension within society.

Ogburn primarily focused on the disparity between 'material culture' and 'non-material culture.' Material culture encompasses tangible aspects of society, such as technology, scientific discoveries, and physical infrastructure, which tend to evolve at a rapid pace. Non-material culture, on the other hand, includes intangible elements like customs, beliefs, values, laws, philosophies, and social institutions, which are often more resistant to change and tend to lag behind.

The core idea is that technological advancements (material culture) often create new social conditions and possibilities, but society's norms, values, and institutions (non-material culture) do not immediately adapt to these changes. This delay in adaptation creates a 'lag' that can result in social problems, ethical dilemmas, and societal friction.

Classic examples of cultural lag include: the rapid development of genetic engineering and artificial intelligence (material culture) outpacing the establishment of ethical guidelines and legal frameworks (non-material culture) to govern their use; the internet's transformative impact on communication and information sharing (material culture) challenging traditional notions of privacy, copyright, and social interaction (non-material culture); or the slow adaptation of educational systems to prepare students for jobs in rapidly evolving technological landscapes. Ogburn argued that this lag is a persistent feature of modern societies characterized by continuous innovation.

Understanding cultural lag helps explain many contemporary social issues and the challenges societies face in integrating new technologies and ideas while maintaining social cohesion and order. It highlights the dynamic interplay between different cultural components and the inherent difficulties in achieving perfect societal equilibrium amidst constant change.