Generally speaking both amongst traditionally brought up Muslims and Orthodox Jews it is considered rude to look directly at the person you are talking to, if that person is either of the opposite sex, or older than you are, or your social superior.
Chinese and Japanese tend to adhere to this rule as well.
It is, of course, the direct opposite of the good manners of the Western world that require you to look at the person you are speaking to, or who is speaking to you.
Hands out of your pockets- rule is another one. In the far East it is rude to display your hands more than necessary, so wearing a kimono, you tuck your hands into your sleeves.
Nowhere in the East is it considered correct for young or younger men to smoke in the presence of their elders.
And our generation of Europeans were taught it was rude for a child to sit down without permission if grown-ups were standing. We had too, to rise if an adult came into the room both at home and at school.
In Denmark, I had to remember as a child to curtsey to grown-ups when greeting them or saying good-bye and not to extend my hand for a hand-shake until the grown-up put out his or her hand. If the grown-up you were with in the street or a shop stopped to talk to a friend, the accompanying child curtsied (or bowed, if a boy).
Just back from holiday, I automatically did so in Glasgow and people stared as if I was crazy, or worse, taking the mickey!
Today's children frankly disbelieve us when we tell them this.