The early adopters set the trends once they have carved niches for themselves! They create them around their own skillsets. They don’t exist before then, and that explains how research fads come into being and why there are always one or two leaders at the very origin of a field! The very language of the field grows around these individuals!

Sorry if I got somewhat carried away with that insight. It just happens to support something I called the “initialism” principle, which I had largely discarded a while ago. That principle states that the present state of nearly everything is influenced by its origin. Please don’t mistake it for determinism; it makes no claim that the present state of things is exactly determined by the state of their origins.