Varna is said to be based on traits, but how should one identify the traits? It is possible to know one’s character as he/she becomes mature, but would it not be good if we identify it before starting the education? If not a person who is never interested in vedas and philosophy but in say tool making might be forced to waste time in learning BrahmaSutras.
Is that the real reason for Upanayana? After Upanayana a person is called Dvija or twice born. Why is it so? Is their any linkage between this and Varnashrama? Read On:
(1) As per “Shodasha Samskara” a brahmin child should not be considered as a brahmin till he gets his Yagnopaveeta, a license to study BrahmaGnyaana. If the child dies before the Upanayana, the child is buried not cremated.
(2) It is known that Yagnopaveeta was also worn by ladies during vedic period when they were studying philosophy, later when they were reserved to do house-chores (Unfortunately) they were spared from wearing it or getting Upanayana done.
(3) In older days Upanayana was done for all three major sub groups except the last “Shudras”.
(4) There is a rechristening ritual in Upanayanam, a person gets a new surname. Usually since it is done only within Brahmin community, the surnames are “Sharma”, “Acharya”, etc. But I take liberty to think that we also get surnames like “Varma” which indicates the person is going to be a Kshatriya, or “Shreshti – Shreeeyam Ishtathi iti Shreshtihi, one who loves wealth is a Shreshti, which got its vernacular version of Shetty” for Vysya. Also it is possible to enjoin yourself to a new Gothra, and then you are called “Gothrapathyam Puman” son by Gotra. There are many Gotra lineages that were thus adopted .(I have the whole Gotra tree with me, but cant put it here it is so huge)
(5) As per Manu Smriti, all three subcasts can study Brahma Gnyaana, but only Brahmins are supposed to teach it, similarly Shastra(Weapons) and Vyapaara(Business). It also tells that at dire situations people can change their professions, but generally that is not preferred. Also there is clear specification that if a person and his family chooses a different profession and continues to be in that profession for 7 generations the varna changes. Which is a clear evidence that Varna is primarily a trait, but linked to birth only in smritis for the sake of convenience.
Manusmiriti takes the easy step of associating traits with birth. No text explains how to formally join/change a varna, other than jata-varna. And hence starts my imagination of linking Upanayana as a device to change the Varnas:
Any child born is neither a Brahmin, nor a Kshatriya or Vysya. They all fall into the default bucket of Shudras (Courtesy, first point above). Children of all four Varnas were put under observation. The various behavioural characteristics were analaysed and then parents and society together would decide to which classification the child seems to be fit. Corresponding to the trait of the child respective Upanayana samskaras are done for the child to join the Varna of Brahmana, Kshatriya or Vaishya. If the child is very servile, without having any independent decision making ability, the child is classified as a Shudra and no Upanayanam is done. Hence except Shudras all are called Dvijas, the twice born. Thus even if you consider the Varnas tied to birth, it is tied to the second birth not the first.
Possible Reasons for Upanayana Samskara to be restricted to Brahmins.
Because of marriages strictly within Varnas and genetics, the offsprings might have started to show behavioural characteristics of the same varna as that they were born. This pattern would have caused people to not to do any Upanayanam and associate the child’s Varna automatically with the first physical birth. However Brahmins who are more traditional continued the process of upanayanam but still they kept the child in the same Varna. But they too laxed the ritual to females and retained it only for males.