Peter Heather’s Empires and Barbarians begins with a chapter summarizing grand theories of demography and social transformation among near-prehistoric peoples of Europe.
Both classical sources and pre-1960 scholarship tended to explain events in terms of the wholesale migration of demes of people. In later years, it has become more common to deny the importance of demic migration, instead invoking elite migration and dominance, demic diffusion, or other schemes.
I’m not reviewing the chapter here but I wanted to record a quote from Heather’s page 19:
[A] basic equation has grown up in the minds of some archaeologists between any model of the past involving population movement, and simple-mindedness. As a recent introduction to early medieval cemeteries put it, avoiding migration in explanations of archaeological change 'is simply to dispose of an always simplistic and usually groundless supposition in order to enable its replacement with a more subtle interpretation of the period'. Note the language, particularly the contrast between 'simplistic' and 'groundless' (the world dominated by migration) with 'more subtle' (any other kind of explanation). The message here is loud and clear. Anyone dealing with the geographical displacement of archaeologically observable artefact types or habits, who wants to produce an account of the past that is at all 'subtle' or 'complex', should avoid migration at all costs. The tables have turned. From a position of overwhelming dominance before the 1960s, migration has become the great Satan of archaeological explanation.
What a way of capturing the sneers of critics following a fad. Better to be “subtle” and “complex” than “simplistic”!