Cultural conventions border on the arbitrary. They are “real” only in the social sense of reality. They are meaningful only because we give them meaning. But that doesn’t mean that they don’t evoke real emotional responses from people when they are violated.
One example of a cultural norm in the U.S. is the removal of price tags on gifts. We all know to do this, because we were told by our parents to do that. But why do we take off the tags on gifts? It’s a cultural convention. There could be a culture in which one leaves them on in order to make sure people know the value of the gifts. There were plenty of gift cultures in the past which emphasized the size and value of the gifts which could have evolved, in a modern context, to giving gifts with the price tags still on. In each case, people practicing the cultural norm would be offended and appalled at violations such as leaving the price tag on, or taking it off, respectively.
I have always been able to see through cultural norms and conventions such as these. And I suspect this is a general trait of those on the spectrum. It would explain why people with Asperger’s marry people from other cultures at a much higher rate than the general population. If cultural norms are merely conventions, they aren’t “real” in the physical sense, and therefore one can easily adjust to different norms. If you are on the spectrum, at least.
This ability to see through cultural norms as merely conventional is also one of the things that gets autistics in trouble with neurotypicals, who do not think them conventional, but take them seriously. This would create a great deal of social awkwardness, some interpreted as rudeness, if autistics are constantly ignoring social conventions because, seeing them as merely conventional and arbitrary, they don’t think them all that important. They fail to take into consideration the fact that everyone not on the spectrum does take them seriously. Sometimes deadly seriously.
Yet, for there to be cultural change, there have to be people around who question the cultural norms, pointing out that they are in fact social constructs. Thus, people on the spectrum could contribute to cultural evolution; they would keep things changing by always questioning. As such, they are an important part of any society, even if this role is utterly unappreciated and often outright disdained.