How much of human behaviour and expression is directly externally effectual? If a person is in a bad mood, in what ways does their bad mood impact the external world, including other people, in a direct way? In most cases I imagine that there is very little in terms of direct effects, that the majority of cases only affect the internal state of the mind. I think of the internal state as a buffer, or to use the more colloquial term, a sponge, that accumulates data without emitting it directly. Only after some threshold of accumulation is it manifested externally; it thus operates in bursts. Different affecters of the internal state may have different half lives, that is the time until their impact will be emitted externally; I think of it working similarly to the absorption and emission of photons in atoms, with direct affecters being analogous to photons that are immediately reflected, and possibly partially absorbed too.
Following this model, we can attribute different forms (frequencies in wave lingo) of human behaviour, that is the internal state actuating external change, to different affecters of varying amplitudes and latencies. That is to say, behaviour is due to a combination of mostly historical and some immediate affecters.
This model can be used to explain emergent behaviour, from molecules forming larger structures to humans forming tribes and societies. If we simply examine the external bursts emitted by people, ignoring their internal state, then I suspect that we can derive a fairly good macro-model for emergent behaviour, applicable to such areas as economics or sociology.
More interestingly, this suggests that if you can predict how a global action, such as a policy or law, will impact the behaviour bursts produced, then you can reliably predict the macro-societal behaviour it would yield. This by definition completely ignores the impact of said policy on the internal states of people, which we do care about, being human (unlike the internal states of individual molecules, say). I think that this is a key point that is ignored, or at least grossly undervalued, by many societal systems (by societal systems I mean systems designed to run societies, including economic systems, social systems, etc). I don’t have any good ideas as to how this problem can be addressed. I find the reverse problem of defining an individual-centric model, potentially at the expense of society, to be even more difficult to work with.