Which of the following best describes cultural lag?

Concept. Culture has two parts that change at different speeds. Material culture is the tangible side — tools, machines, technology, objects and infrastructure. Non-material culture is the intangible side — beliefs, values, norms, customs, laws and institutions. William F. Ogburn (Social Change, 1922) argued that the material side generally changes first, while the intangible side needs time to adjust to it. The interval during which that adjustment is still incomplete is what sociologists call cultural lag.

Applying it here. The description that fits this definition is "the delay in non-material culture catching up with the changes in material culture". A familiar illustration: smartphones, social media and, more recently, AI tools spread through everyday life within a few years (material change), while the etiquette, privacy norms and data-protection laws governing their use formed only much later (non-material adjustment). The stretch of time in between is the lag, and Ogburn treated it as a normal, recurring feature of rapid technological change rather than an exception.

Contrasting the other descriptions.

• "A smaller cultural group within a larger culture" defines a subculture — a group identified by distinctive practices inside a wider society. It is a statement about group membership, not about two parts of culture changing at different rates.

• "A subculture that opposes the dominant culture" defines a counterculture — a group identified by rejection of mainstream values. Again a classification of groups, with no reference to timing or adaptation.

• "The gap between ideal culture and real culture" names the ideal-versus-real culture distinction — the distance at one point in time between the norms a society professes and the behaviour its members actually display. It is a gap between principle and practice, not a delay in adapting to material change.

Result. Cultural lag is defined by the time gap in adaptation: material culture moves ahead, and non-material culture — norms, values and laws — catches up later. The description built on that delay is therefore the correct one.