I think you’re right that intersubjectivity plays an important role in developing the ability to self-attribute. But to take Metzinger’s position as an opposing perspective, he explicitly states at one point that the “we” is dependent upon the “me” – logically, evolutionarily, and in individual development. The problem is that the substance to this claim is only going to be developed in the 2nd half of his book, i.e. the part I haven’t read yet.

But to suggest a way he might substantiate this claim, one of his key distinctions is 3 types of ‘global availability’ for a system – that is to say, the dispositions a neurobiological/representational system can take towards subsets of itself. Phenomenologically, this appears in the fact that we can focus on various aspects of our experience. For Metzinger, there are 3 variations, however: behavioural, attentional and cognitive. Behavioural means that we can react or act upon a stimulus, attentional simply means that we can focus our nonconceptual attention on it, and cognitive means that we can conceptualize it. (This is where blindsight is particularly interesting, because cognitively and attentionally, those with blindsight can’t focus on a particular visual area. But behaviourally, they still show the ability to grasp and use information from their senses.)

So to return to your example, it might very well be the case that the child can behaviourally and attentionally focus on their ’self’ (as a product of neurology). But presumably it’s only with the resources provided by the linguistic community that it gains the ability to put those aspects into concepts. That being the case, though, there’s already been a nonconceptual acknowledgment of the first-person perspective being ‘mine’ in some sense.

But, to be sure, Metzinger has largely stayed away from any issues of intersubjectivity so far. In the first half at least, he’s focused almost exclusively on the neurobiological determinants of individual experience.

There’s something about violating expectations that triggers the need to generate explanatory statements regarding intentionality. Only when the intuitively obvious behavioral path is deviated from is there any reason to question one’s motives. It’s through social interaction that a child comes to understand what’s expected; eventually the child comes to expect this of himself. And so he learns to introspect about motivations even when nobody’s watching or asking.

At the same time, children learn to understand language by inferring the speaker’s intentionality. When the mother points to the mess on the floor and says “Look at this mess,” the child has to understand that the mother, through symbolic communication, is establishing a joint attentional frame that involves herself, the child, and the spilled cereal. The child then has to align his own attention with that of the (m)other in order to know what she’s pointing to and talking about. And he can almost surely infer from facial expression, and tone of voice that the mother’s affect regarding the cereal isn’t a happy one, based partly on prior encounters with her, partly on what he knows he feels like when he sounds like she does.

Of course none of this addresses the biological determinants of self-statements about internal mental states. I’m just thinking about the intrinsic intersubjectivity of even the most presumably intrasubjective self-attributions.