Few practices are as widespread among human cultures as the ceremonial wedding of a woman and a man. Individual impulses to ensure the survival of one's genes mesh with society's desire to establish family units. This may all sound very unromantic, but marriage is serious business—much too serious, some might say, to be left to extremely young men and women. Surely the elders know best. ＿＿（11）＿＿ The basics of matchmaking are simple. After collecting information about marriageable men and women, a matchmaker decides which would be a good match. Sometimes the matchmaker represents the male or his family and therefore assesses available females. ＿＿（12）＿＿ In still other cases, the matchmaker is an independent judge, representing neither side but hoping to make a choice that will satisfy both. We've already hinted at one motivation for matchmaking—the belief that the people getting married are too young to make a wise decision. 13 Even with older teens or people in their early 20s, a society might encourage matchmaking in the belief that young people, blinded by the sexual attractiveness of a potential mate, cannot shrewdly choose someone who could make a good lifelong partner after the beauty of youth fades away. In the main, matchmaking has historically worked to preserve the integrity of certain social groups and prevent the weakening of the group by intrusion from outsiders. ＿＿（14）＿＿ The Hindu caste system specifies distinct social roles for people based on their ancestry, a system that would become hopelessly confused if young people married freely between castes. Matchmaking, usually by the elder women of families looking to arrange a marriage, was a mechanism for ensuring that caste boundaries were observed. ＿＿（15）＿＿ Countless religious websites and church organizations aim to keep Catholics, Muslims Muslim, Jews Jewish, or Baptists Baptist by making it easier for them to meet and marry others of the same religion.