The Age Requirement for Bar/Bat Mitzvah
How Old is Old Enough?
At the age of majority, Jewish boys and girls take on the obligations of the mitzvot, or commandments. In traditional Judaism, men and women have different, though overlapping, sets of obligations. With some exceptions, women generally are not obligated to perform time-bound commandments, like listening to the shofar or saying the Shema. Men, however, were obligated to perform all of the time-bound commandments. As a result, the age of majority historically had different connotations for boys and girls. Whereas the obligations taken on by a young man at bar mitzvah were public and visible, a young woman's fell mostly in the more private realm of the "thou shalt nots." Today, as women in the liberal movements have taken on obligations that were traditionally reserved only for men, the age of majority has come to have a more public meaning for girls: at age 12 (or 13 in many liberal synagogues) they can be part of a minyan (quorum of ten) or wear tallit (prayer shawl) and tefillin (phylacteries). Over the past several decades, more adult women have had Bat Mitzvah ceremonies. While they are technically obligated in the mitzvot at a younger age, these ceremonies are public affirmations of their place in the Jewish community which was denied to them when they were young. Reprinted with permission from Life Cycles in Jewish and Christian Worship (The University of Notre Dame Press).
While the age of majority is not designated as such in biblical literature, the age of 20 seems to be the standard for purposes both of taxation (e.g., Exodus 30:14) and conscription (e.g., Numbers 1:3, 24). This age seems to apply equally to males and to females (see Leviticus 27:4-7), albeit only for taxation.
The age for moral responsibility seems to be the same. In Numbers, God distinguishes those of age 20 and above, guilty of mutinous, faithless complaints, from "your little ones" and "your children," who alone will arrive in the Land of Israel as promised (Numbers 14:26-35). So the age of 20 marked the transition to adulthood in the biblical period, but no rite marking the transition is recorded there.
In rabbinic literature (primarily the Mishnah and Babylonian Talmud, with respective editorial dates of approximately 200 CE and 550 CE), the ages of 12 years and one day for girls and 13 years and one day for boys--the ages widely regarded traditionally as the threshold of adulthood--begin to take on significance.
This change from the biblical age of majority may reflect outside influence. At this point, a 13-year-old boy is obligated to participate in public, religious fasts. Likewise any vows he might make are to be regarded as valid.
Two criteria are given for this chronological marker for boys: physical maturation and moral discernment. The first is reflected in the assumption that at about that age, pubic hair appears. "A boy who has grown two [pubic] hairs is subject to all the commandments in the Torah."