I do not know of any definite statement on this point, but it is interesting to note that among the Jews the age of twelve seems to have been considered the age of accountability. See The Desire of Ages, p. 75. Much is said in the Spirit of Prophecy about the importance to the early years of the child's life, the first three years, the first seven years, etc. The proper training during these early years is vital. (Bessie Mount)