Final answer:
The practice of women giving men chocolates on Valentine's Day in Japan is an example of the influence of customs on behavior in different societies. Customs can also affect economic decisions, such as Japan's trade policies on culturally significant products like rice.
Step-by-step explanation:
The fact that in Japan women give men chocolates for Valentine's Day is an example of how customs can influence behavior in different societies. These social customs are traditions or habits that are considered a typical part of the culture and social life of a particular group of people. In the context of international relations, countries may have different practices that shape their economic decisions. For instance, Japan may restrict trade on imported products like rice to protect a culturally significant industry, even if another country has a comparative advantage in its production. This protection of national identity can influence trade policies and behaviors within a society, reflective of their customs.