Vygotsky argued that anything must have existed outside, that is, in the social world, before it can exist inside, in other words, in our head.
But I argue, and today I had new evidence supporting this, that this is a to-and-fro process. It doesn't work in only one direction (eg, internalisation) but in both directions (ie, externalisation too). And it doesn't just occur once and that's it. It's recurrent.
My participant said today that he wanted to take part in my experiment, where he was required to record himself on video, because "I can think things in English, but I can't hear myself". I take that to mean that he can internalise things from the outside world, and then externalise them by speaking, but he can't internalise them again, which is what the video-recording session could do for him in the end.
I hope this makes sense.