|The ring finger on this hand is extended (left hand).|
|Latin||Digitus IV manus, digitus quartus manus, digitus anularis manus, digitus medicinalis|
|Artery||Proper palmar digital arteries,
dorsal digital arteries
|Vein||Palmar digital veins, dorsal digital veins|
|Nerve||Dorsal digital nerves of radial nerve,
Dorsal digital nerves of ulnar nerve,
Proper palmar digital nerves of median nerve
The ring finger is the fourth proximal digit of the human hand, and the second most ulnar finger, located between the middle finger and the little finger. It is also called digitus medicinalis, the fourth finger, digitus annularis, digitus quartus, or digitus IV in anatomy. It may also be referred to as the third finger.
According to László A. Magyar, the names of the ring finger in many languages reflect an ancient belief that it is a magical finger. It is named after magic or rings, or called nameless (for example, in Chinese: 无名指, unnamed finger). In Sanskrit and other Indic languages, the name for the ring finger is Anamika ("nameless").
The wedding ring 
Before medical science discovered how the circulatory system functioned, people believed that a vein of blood ran directly from the third finger on the left hand to the heart. Because of the hand-heart connection, they chose the descriptive name vena amoris, Latin for the vein of love, for this particular vein.
Based upon this name, their contemporaries, purported experts in the field of matrimonial etiquette, wrote that it would only be fitting that the wedding ring be worn on this finger. By wearing the ring on the third finger of the left hand, a married couple symbolically declares their eternal love for each other.
In Western cultures, a wedding ring is traditionally worn on the ring finger. This developed from the Roman "anulus pronubis" when the man gave a ring to the woman at the betrothal ceremony. Blessing the wedding ring and putting it on the bride's finger dates from the 11th century. In medieval Europe, the Christian wedding ceremony placed the ring in sequence on the index, middle, and ring fingers of the left hand. The ring was then left on the ring finger. In a few European countries, the ring is worn on the left hand prior to marriage, then transferred to the right during the ceremony. For example, a Greek Orthodox bride wears the ring on the left hand prior to the ceremony, then moves it to the right hand after the wedding. In England, the 1549 Prayer Book declared "the ring shall be placed on the left hand". By the 17th and 18th centuries the ring could be found on any finger after the ceremony — even on the thumb.
Left or right Hand 
In some Orthodox Christian, Roman Catholic and Protestant countries such as Greece, Georgia, Poland, Austria, Germany, Norway, Denmark, Spain, Chile, Venezuela, Colombia and India, the wedding ring is worn on the ring finger of the right hand.
In other countries, such as France, Ireland, Sweden, Italy, Slovenia, Hungary, Turkey, Brazil, Egypt, Mexico, Canada, the USA and the UK, it is generally worn on the ring finger of the left hand, although right hand wearing is becoming more common.
The ring is more noticeable on the right hand due to the traditional shaking of right hands in greeting.
Several traditions exist in traditional Jewish wedding ceremonies: most commonly today, the ring is placed on the index finger; but other traditions record placing it on the middle finger or the thumb. Today the ring usually is moved to the ring finger after the ceremony. Some Jewish grooms have adopted wearing a wedding ring.
A wedding ring is not a traditional part of the religious Muslim wedding; wedding rings are not included in most Islamic countries. However, if a wedding ring is worn in an Islamic country, it may be worn on either the left (such is the custom in Iran) or the right ring finger. As opposed to the wedding ring, use of a ring to denote betrothal or engagement is quite prevalent in Muslim countries, especially those in West and South Asia.
Rings are not traditional in an Indian wedding. However, in modern society it is becoming a practice to wear rings for engagements and not for actual marriage. Though the left hand is considered inauspicious for religious activities, a ring (not to be called wedding ring) is still worn on the left hand. Men generally wear the rings on the right hand and the women on the left hands.
In Sinhala and Tamil culture, the groom wears the wedding ring on his right hand and bride wears it on her left hand ring finger. This can be seen in countries like Sri Lanka where there is a rich Sinhala and Tamil cultural influence in the society.
Scientific study 
|This section requires expansion with: Studies not about the ratio between index and finger. (November 2012)|
The ratio between index and ring finger is believed to be linked to exposure to testosterone in the womb. On average, men tend to have longer ring fingers and women longer index fingers. The higher the testosterone, the greater the length of the ring finger and the more "masculine" the resulting child – whether male or female. The longest ring finger is known as the "Casanova pattern".
In a study of stock traders, Cambridge University researchers found that the most successful had a relatively long ring finger. According to this study, the finger-length ratio was boosted by higher levels of testosterone in the womb during a crucial phase of gestation. Traders with long ring fingers made up to 11 times the earnings of their counterparts, the study found.
Scientists at the University of California, Berkeley found the difference in the length between women's ring fingers and index fingers tend to be greater for lesbians than straight women. The same study also found that a greater difference in length of men's ring fingers and index fingers for gay men with several older brothers as compared to straight men.
Scientists at the University of Bath found that children who had longer ring fingers are better with numbers-based subjects such as mathematics and physics, which are traditionally male favorites. 
- "Third finger". Dictionary.com Unabridged. Random House, Inc. Retrieved 2012-08-05.
- Magyar, László A. "Digitus Medicinalis — the Etymology of the Name" Actes du Congr. Intern. d'Hist. de Med. XXXII., Antwerpen. 175-179., 1990, retrieved September2,2009
- Why in the Orthodox tradition do we wear the wedding ring on the right hand?, antiochian.org
- David Sperber, in: Daniel Sperber, Minhagei Yisrael Vol. 4, Jerusalem 1995, pp. 92-93 (Hebrew)
- "A Sri Lankan Tamil Hindu Wedding".
- Laurance, Jeremy (14 January 2009). "Success isn't written in the stars, it's in the length of your fingers". The Independent. Retrieved 28 May 2009.
- Alleyne, Richard (13 January 2009). "Ring finger length linked to City stockbrokers' success, claim scientists". Telegraph (Telegraph Media Group Limited).
- "A finger on sexuality". BBC News. 29 March 2000.
|Look up ring finger in Wiktionary, the free dictionary.|
- Online Ring Sizer
- Wedding rings in Germany - right or left, in German
- Archive of a 1998 article in a Flemish newspaper about the place of the wedding ring in the Low Countries