Pavlov began it, thinking he could explain it with dogs.
Thorndike and Skinner experimented further, but it was lost in the Law of Effect and thousands perished in drill and practice.
Then Dewey found it and held it for the desires and motivations of all, while the Gestalt, on the edge of things, encouraged insight and a view of the whole.
Piaget discovered how it worked, but separated it from its core and it was almost lost again.
But then Bruner rescued it and described how it could work, whilst Wood built a tower for it. Then Vygotsky, King of the Tower, opened up the tower for the people to talk and communicate and interact with it. Yet this, his greatest feat, was overlooked by another, the Zone of Proximal Development, which whilst instilled with truth was a distraction from the biggest triumph. And men came and made the most of this distraction, like Von Glasserfeld with his love of the subjective and the internal.
And some, yea, even Bloomfield, were overcome with this distraction and did comment slightly sceptically on the power of social interaction, with words like 'construed' and 'apparent'.
But then Cobb came forward, and Ernest, adding social knowledge to his three worlds, and finally Jaworski with his understanding of story and negotiation
And thus it was that Bloomfield laid aside his slight scepticism and came to declare that knowledge is socially constructed between groups who share meanings.
And so it was that one day all people would understand that knowledge exists neither externally to the individual nor internally; but on the tender wisps of the webs that lie between individuals; on the cusp between the external and the internal; on the expectations and obligations that turn individuals into people.