I agree. It is indeed unsurprising and expected that states of the mind produce effects in the body. By thinking of a cold beer, good food, or beautiful people one can easily evoke stimulating effects in the body. States of the mind produce effects on the body as well, such as facial expressions, movement of arms, legs, or the whole body. Via these our minds can have major effects on our environment.

According to Searle experiences exist in an ontologically subjective domain in an ontologically objective reality. In this sense experiences are ontologically irreducible to physical states. But that does not exclude the possibility that they are causally reducible to physical states. Unlike a video recording the experience is a causation of brain events whose content is set by the object's present features. Many people may experience the same object, but seldom the exact same set of features, and never with the same brain.

An even more telling situation is presented by the mind which is not the body. If we take the non-reductive accounts of mind Wayfarer holds so dear, the presence of a mind which is not any particular instance of body, it can only form a causal relationship with the body to produce the placebo effect.

States of particular concious experiences, various beliefs, must be a material cause-- states of the world which bring about causal impact on others, on bodies.

In the context of non-reductive experience, the placebo effect isn't a problem for materialism, but rather a prime example of materialism in action. Experiences themselves are knowable states of the world which cause others.

Objectivity and subjectivity are co-arising and mutually dependent.

Subjectivities are objective-- it's true my states of experiences exist and cause other states (including of my own body).

There is no "dependency" because the aren't seperate at all. I do not, on one hand, have objective experiences and subjective experiences on the other. All my experiences are subjective (MY experience) and objective (existing) all at once.

what I said.

I agree that there is no absolute distinction between subjectivity and objectivity. I like the co-arising perspective!

I think there is a useful practical distinction though. Saying that something is objectively the case is just saying that nearly everybody would agree that it is the case. That deals with the notion that it is objective that there are two mangos on the table, but that it is subjective that Justin Bieber's 'Baby, Baby, Baby' is a great song.