Explanation
In China, beckoning someone with a single finger, especially with the palm facing up, is considered highly disrespectful and is often associated with calling a dog or a servant. The proper way to beckon is to use all four fingers with the palm facing down, in a gentle waving motion.
Local Tip
To call someone politely, extend your hand with palm down and wave all fingers together toward you.
How it compares elsewhere
Beckoning with a single finger is extremely rude and can be seen as a challenge or insult.
Beckoning with the index finger is considered rude; use a gentle wave with all fingers and palm down.
Beckoning with the index finger is common and generally acceptable in casual settings.