Kippah/Yarmulke
Why Jewish men wear a kippah/yarmulke
Clothing worn by Jews usually varies according to which denomination of Judaism they adhere to.
Orthodox Jewish men always cover their heads by wearing a skullcap known in Hebrew as a kippah or in Yiddish as a yarmulke. Women also cover their heads by wearing a scarf or a hat.
Liberal or Reform Jews see the covering of the head as optional.
Most Jews will cover their heads when praying, attending the Synagogue or at a religious event or festival.
Wearing a skullcap is seen as a sign of devoutness.
The most common reason (for covering your head) is a sign of respect and fear of God. It is also felt that this separates God and human, by wearing a hat you are recognising that God is above all mankind.
History
There is disagreement over whether the covering of ones head is a Torah commandment. However there is some evidence in the Talmud (Jewish teachings) that some form of head covering is required.
One should not walk bare-headed (the distance of) four cubitsShulchan Aruch, Oracn Chayim, chapter 2
Pride and Identity
Many Jews feel that by wearing a skullcap they are proudly announcing to the world that they are Jewish. This is classed as an 'outward sign' of their faith.
It has also become custom to wear kippahs or yarmulkes of certain colours, sizes and materials as a sign of allegiance to a certain group.