
Question:
Answer:
The Church considers the “age of reason,” i.e., when children have a basic understanding of right and wrong and the ability to choose virtue over sin (see CCC 1849ff.), to be roughly the age of seven. That’s why children typically go to their first confession before their First Communion in second grade.
Young children sometimes touch themselves in a private area without sinful intent, including because they may be their exploring their bodies or because they might feel physically uncomfortable, including feeling a need to itch. However, when a child does so to stimulate himself or herself sexually, which becomes a greater temptation when a child enters puberty (given our fallen nature), that is a sin.
It can be difficult for parents to know if their pre-pubescent child is sinning in this manner, so parents should give general counsel to a child not touch himself or herself and then follow up as needed when they see the child engaging in such behavior, with the disclaimer that occasional non-sensual touching is permitted. As the child increases in age and maturity, parents can elaborate further on why such touching is wrong.
For more on this subject, see the Church’s teaching on the distinction between mortal and venial sin (CCC 1854-64), chastity (CCC 2337ff.), lust and masturbation (CCC 2351-52), and purity of heart (CCC 2517ff.; see also 2514-16).