Generally, this melting pot of different cultures and races is very much Westernized in social etiquette, however it is important to recognize certain different cultural and religious characteristics.
Cultural etiquette has been described as the unspoken but assumed behavior that conveys politeness. Therefore it is important that you take the time to learn about and follow "local etiquette". In Malaysia, especially in east coast of the peninsula where there are more conservative (devout) Muslims, there are a few specific rules that visitors should be sure to know about and follow.
Many Malaysians usually greet each other with a less than firm handshake and may then place their right hand over their heart after greeting you as a sign of sincerity. It is also considered impolite to hand or receive anything to a Malaysian with your left hand - as in most Islamic countries the left hand is considered "unclean" and thus insulting. If this makes the action somewhat cumbersome by having to change hands, take the time to do it anyway.
To beckon someone, especially someone who is older, simply refer to them as "uncle" (pakcik) or "aunty" (makcik). People younger than you may also address you with such a term - take it as a compliment! Also, most locals will bow towards the elderly as they walk past them as a sign of respect (though not frequently seen in Kuala Lumpur that much nowadays).
Physical signs of affection in public are frowned upon and on the East Coast of Malaysia, men and women keep a safe distance from each other in public.
There are certain areas of mosques that should not be entered by non-Muslims. Signs are often displayed or people will inform you. Conservative dress codes will need to be adhere to when entering such places (some mosques that are popular or historic will have robes available if you are not properly attired). Shoes must be removed when entering a mosque or temple.
As well, shoes are almost always removed prior to entering a Malaysian home and are sometimes removed before entering some buildings (a collection of shoes at the door is a giveaway that you should remove your shoes).
A common sight will be that most Malaysians eat with their right hand. In many local restaurants this is an acceptable behaviour. If you do wish to follow suit make sure to use your right hand as the left is used for more basic bodily functions (which explains the reason for the above greeting etiquette!).
Do not use your right forefinger to point to people, places or give directions. Rather use your right thumb with your four fingers folded underneath (this takes most Westerners some getting used to).
If invited to a Malaysian home, it will be best if you come with a gift. Though this is not a must, the host will definitely appreciate whatever you choose to bring - be it a souvenir from back home, some fruits or drinks purchased from a store around the corner. Even amongst Malaysians themselves, this practice is observed. Bringing a gift is known as carrying buah tangan, which literally means "fruit of the hands".
Lastly, Malaysians are nothing if not hospitable and will go out their way to offer guests a drink or snack - it would be impolite to refuse..
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