In discussing structural coupling, Luhmann writes,
In their irritability . . . both consciousness systems and the communication system society are completely autonomous. Irritations arise from internal comparison of (initially unspecified) events with the system’s own possibilities, especially with established structures, with expectations. There is hence no irritation in the system’s environment and there is no transfer of irritation from the environment into the system. It is always a construct of the system itself, always self-irritation–albeit occasioned by environmental effects. The system then has the possibility of discovering the cause of the irritation within itself and learning from this discovery or attributing the irritation to the environment and treating it as an “accident” or seeking its source in the environment and exploiting or eliminating it. (The Theory of Society, vol 1, pp. 66-67.)
A system, in other words, cannot be directly irritated by its environment. Any irritation arises from the comparison of an encountered event with established structures, expectations, or “business as usual.” The cause of the irritation lies within the system; it is simply a comparison. For example, if a child picks up a glass of wine thinking it is grape juice and takes a gulp (as I once did), he will be shocked, startled, disoriented, etc. He was obviously expecting to taste grape juice. Now, if the kid is stupid he will take another sip expecting to taste grape juice, as if the first taste was just a fluke. Or he can change his expectations, and this equates to learning. In any case, the surprise results from an internal comparison between a sensory event (the taste) and an expectation. Clearly, the wine itself did not cause the startle response. The response is structurally determined.
To take a social example, if while in a grocery store I see an adult violently slap a child, I will be startled, as well as angered. However, the slap itself did not cause my response. My psychic system produced the response by comparing the slap to my own expectations for public behavior. If I am not started, it means I expect to see these kinds of events on a regular basis.
In terms of structural coupling, there are at least two different kinds. In the grape juice/wine situation, there is a physiological structural coupling between my taste buds and the wine (wine molecules or whatever). The brain compares the taste of nothing (the experience of not having a drink if my mouth) with the taste of the wine. In addition, the consciousness system comes into play with the structural coupling between the taste and my expectations. If I was am expecting wine and I’m familiar with this particular wine, there won’t be much of a response other than just tasting it. If I’m expecting a good taste and the wine is not good, I’ll be unpleasantly surprised. If it tastes better than I was expecting, I will be pleasantly surprised. The pleasant or unpleasant experience is an affect, or self-generated emotional response.
This analysis relates to Stoicism, defined as the endurance of pain or hardship without a display of feelings and without complaint. If the temperature drops to zero degrees Fahrenheit or lower, as it does regularly this time of year in Wisconsin, I can complain, shiver, and curse the gods, or I can dress in layers and go about my life. Of course, I could also fall through thin ice on a frozen lake and freeze to death, and this would be case of an environmental factor destroying a living system. A system can certainly be destroyed by an environmental factor it is structurally coupled to.