A “tightly-scripted culture” has clear and rigid rules about how “normal people” behave and the penalties of veering away from these social rules are severe. Tightly-scripted cultures tend to be more homogenous and culturally self-contained, i.e. they do not borrow or adapt much from other cultures. For TCKs repatriating to tightly-scripted cultures, the cultural expectations of behavior are obvious and deviations from these expectations are not welcomed.
In contrast, “loosely-scripted cultures” have fewer social rules, more flexible standards for “normal” behavior and are generally more tolerant of digressions from normative behavior. These cultures are also more heterogeneous (i.e. its people are diverse) and pluralistic (i.e. it has diverse systems of organization) and so cultural expectations tend to be vague and can vary.