Keiko was visiting several Latin American cities over the summer, and was very uncomfortable by all the warm hugs and embraces she received when first meeting her host's friends. Keiko's discomfort was likely due to

Display rules

Explanation:

Display rule is the norm of the society in which there are some rules to express the emotions. These norms are not only to express the emotions at the appropriate level but it is also about where to express the emotions.

There would be many situations where the display of the emotion should be suppressed. Because in many cultures it is awkward to display sad and cry at the wedding and cry with happiness at death funeral.

Thus Keirko feels discomfort because of the display rules.