The reason we know our own thoughts better than those of others is simply that we have more sensory data to draw on – not only perceptions of our own speech and behaviour, but also our emotional responses, bodily senses (pain, limb position, and so on), and a rich variety of mental imagery, including a steady stream of inner speech. (There is strong evidence that mental images involve the same brain mechanisms as perceptions and are processed like them.) Carruthers calls this the Interpretive Sensory-Access (ISA) theory, and he marshals a huge array of experimental evidence in support of it.
The ISA theory has some startling consequences. One is that (with limited exceptions), we do not have conscious thoughts or make conscious decisions. For, if we did, we would be aware of them directly, not through interpretation. The conscious events we undergo are all sensory states of some kind, and what we take to be conscious thoughts and decisions are really sensory images – in particular, episodes of inner speech. These images might express thoughts, but they need to be interpreted.
Another consequence is that we might be sincerely mistaken about our own beliefs. Return to my question about racial stereotypes. I guess you said you think they are false. But if the ISA theory is correct, you can’t be sure you think that. Studies show that people who sincerely say that racial stereotypes are false often continue to behave as if they are true when not paying attention to what they are doing. Such behaviour is usually said to manifest an implicit bias, which conflicts with the person’s explicit beliefs. But the ISA theory offers a simpler explanation. People think that the stereotypes are true but also that it is not acceptable to admit this and therefore say they are false. Moreover, they say this to themselves too, in inner speech, and mistakenly interpret themselves as believing it. They are hypocrites but not conscious hypocrites. Maybe we all are
This has far reaching consequences for the premise of ‘free will’. Who has the free will, which consciousness we hold accountable. Or do we just hold the one accountable which can make itself heard even though in reality that consciousness actually hasn’t a clue why his body did what it did and has to concoct an explanation itself.
It also places emotions. Emotions are not ‘our’ emotions but the expression of the state of the other consciousness which for lack of further interaction the neocortex also has to determine via interpretative analysis.