Of course, there is a wider issue than biological maturity, that being the mental maturity of minors, which is often described as being separate from mere biological maturity and severely lacking and not equivalent to that of a legal adult. My contention is that, contrary to popular belief, the commonly accepted claim that adolescents are incapable of exercising rational judgment abilities is not an indisputably correct one. Supporters of this position frequently cite studies conducted with the use of magnetic resonance imaging or functional magnetic resonance imaging that illustrate that the teenage brain is underdeveloped, and that adolescents are thus often incapable of making rational or well informed decisions about significant issues. Yet, as Dr. Robert Epstein, former editor of
Psychology Today, notes in an
article published in Scientific American Mind, thought there is some semblance of a correlation between adolescence and brain development illustrated in these scans, there is no evidence of causation by a natural stage of adolescence. His chief counter-argument references the fact that adolescents have been severely infantilized in modern society, in contrast to the important adult role they played in past times, and it may be this factor that has led to the lack of brain development so commonly assumed to be a natural byproduct of adolescence. As such, it would not be intellectually honest to declare the infallibility of these scans just yet.
There are several studies that have been conducted on the basis of measuring the actual competency of adolescents to make informed decisions, as opposed to highly speculative guesswork based on snapshots of the brain.
An important one is that of Lois A. Weithorn and Susan B. Campbell, which tested four groups of people, aged 9, 14, 18, and 21. The study, entitled
The Competency of Children and Adolescents to Make Informed Treatment Decisions, came to the conclusion that 14 year olds were capable of making medical decisions with a level of competence equivalent to that of legal adults. As partially summarized by Weithorn and Campbell:
"In general, minors aged 14 were found to demonstrate a level of competency equivalent to that of adults, according to four standards of competency (evidence of choice, reasonable outcome, rational reasons, and understanding), and for four hypothetical dilemmas (diabetes, epilepsy, depression and enuresis.)
The findings of this research do not lend support to policies which deny adolescents the right of self-determination in treatment situations on the basis of a presumption of incapacity to provide informed consent. The ages of eighteen or twenty-one as the cutoffs below which individuals are presumed to be incompetent to make determinations about their own welfare do not reflect the psychological capacities of most adolescents."
The earlier study of researchers Grisso and Vierling,
Minors Consent to Treatment: A Developmental Perspective, came to a similar conclusion, the authors stating that
existing evidence provides no legal assumption that minors aged 15 years and above cannot provide competent consent.
Researchers Bruce Ambuel and Julian Rappaport discovered similar results in a study intended to specifically focus on this topic, entitled
Developmental trends in adolescents' psychological and legal competence to consent to abortion. The study confirmed the fact that the rational judgment and decision making capacities of adolescents, (particularly those at or beyond mid-adolescence), were often on par with those of adults.
In a
wide-ranging review of the developmental literature on adolescents abilities to make rational decisions about medical treatment, researchers Kuther and Posada confirmed that,
the literature in developmental psychology has shown that adolescents are able to make meaningful decisions and advocates for youth have argued that researchers must respect the autonomy rights of children and adolescents, thus confirming the legitimacy and validity of the previous studies to a great degree.