Answers? False, false, and false. All three gestures are acceptable in American culture but in many others are not—they may even be insults or obscenities. The meaning or emotion that a gesture communicates tends to be regional, cultural, or national, a good thing to remember when you are working with persons from other cultures or traveling to places new to you. Every nonverbal signal—gesture, facial expression, stance—communicates something, whether deliberate or accidental. You don't want those signals to communicate what you don't mean.
Most organizations comprise people of various cultures, even if they were all born and raised in the same country. Large organizations and, by definition, global ones, have an ongoing need to help people of varying backgrounds and behaviors understand one another, use their strengths, and diminish any obstacle that inhibits cooperation, collaboration, and progress. Individuals have that same need, especially when their success in a project or a career requires an ability to work as a team or to lead one.
Dozens if not hundreds of elements form a culture, a configuration made even more difficult to traverse when not every member of a culture shares them all. Appearance and matters of dress are elements, as are habits of speech and expression, perspectives on time, ways of thinking, prioritizing, explaining, and illustrating. Some cultures are direct, some indirect. Acceptable levels of formality may range from casual to ceremonial. Some value the individual while others hold a group in highest esteem. Beliefs concerning power or hierarchies may differ, as may the ways in which humor is shown.
How do you know what's acceptable? In part, your experience contributes to your knowledge base. Places you have lived or worked and people you know or have known can help you understand a culture's dimensions. Your common sense and powers of observation help, too, whether the culture is corporate or foreign or both.
Research helps. A Google search of cultural differences yields millions of sources—articles, books, images, videos—that describe practices and behaviors in regions small and large. Many organizations offer workshops alerting employees not only to differences they may encounter but to ways of navigating unfamiliar territorial waters. You and your colleagues will benefit from such preparation.
If you find yourself in a situation for which you are unprepared, try to avoid misinterpretation by gesturing less or keeping gestures neutral—not above the shoulders or below the waist, whole hands, fingers together. Attend to how members of the culture behave; follow their lead as much as is appropriate.
Mind their manners.