Final answer:
Social customs such as greeting practices vary globally, with female acquaintances in Colombia kissing each other on both cheeks, while such actions might be reserved for closer relationships in other cultures, sometimes leading to culture shock.
Step-by-step explanation:
Greetings about social customs can greatly vary from one culture to another. For instance, in Colombia, it's a common practice for female acquaintances to greet each other with two kisses on the cheek. This may seem unusual to people from cultures where such a gesture is reserved for close friends or family members. The act of kissing on the cheek can be seen in other cultures too; for example, Rodney experienced this when he met his host family in Italy, leading to a culture shock as men in his homeland generally do not kiss each other unless romantically involved.
Moreover, what is considered appropriate physical interaction among friends can vary as well. For instance, in many parts of Africa and the Middle East, it's not uncommon for male friends to hold hands, which might be interpreted differently in the United States. These diverse customs show the rich tapestry of human social behaviors across the world, demonstrating that what is deemed polite or friendly in one culture could be surprising or misunderstood in another.