As a college graduate trained the biological sciences, I would ordinarily be expected to be knowledgeable in classical anatomy or natural sciences. But ever since the widening scope of interdisciplinary studies, biological sciences is or has never been expected to research the molecular sciences alone. There are the anthropological sciences of biology, most notably, the opposable thumb from the pioneers of Stephen Jay Gould. What interests me at the very least as a fleeting thought, is that human maturity is an oversimplified legal definition. Norms of society are unwritten and closely followed through oral traditions, but close analysis, or lack thereof, points out that youthful behavior exists long into old age. It is almost a hallmark that old age contains a rebirth of youth, either through grandparentage, or renewed leisure time from retirement. Some people who age accept aspects of very late age at an early age of seniority, whereas others retain aspects of youthfulness as long as possible. Puer aeternus is a behavior of childishness in adults when another societal norm is expected. In the absence of a contradictory societal norm, Puer aeternus is a norm in old age. It complements what is old and challenged by years of abandonment or subservience. One potentially false label given to elders by jealous relatives or caretakers are that they are senile. But such a label lacks the critical rumination of the normally transitioned human mind in old age. The old are not senile, Their awareness has simply required more time to arrive at understanding their surroundings. Through creativity, research, and observation, youthful behavior in old age can be determined to be a normal process where opposition is shaped in agenda by contemporary fads, uncritical analysis, and hasty opportunists.
Maturity is much more culturally-dependent than it is often viewed to be.