ScienceDaily (Oct. 8, 2009) — A 16-year-old might be quite capable of making an informed decision about whether to end a pregnancy – a decision likely to be made after due consideration and consultation with an adult – but this same adolescent may not possess the maturity to be held to adult levels of responsibility if she commits a violent crime, according to new research into adolescent psychological development.

“Adolescents likely possess the necessary intellectual skills to make informed choices about terminating a pregnancy but may lack the social and emotional maturity to control impulses, resist peer pressure and fully appreciate the riskiness of dangerous decisions,” said Laurence Steinberg, PhD, a professor of developmental psychology at Temple University and lead author of the study. “This immaturity mitigates their criminal responsibility.”

The findings appear in the October issue of American Psychologist, published by the American Psychological Association.

Steinberg and his co-authors address this seeming contradiction in a study showing that cognitive and emotional abilities mature at different rates. They recruited 935 10- to 30- year-olds to examine age differences in a variety of cognitive and psychosocial capacities.

The participants took different tests measuring psychosocial maturity and cognitive ability to examine age patterns in numerous factors that affect judgment and decision-making. The maturity measures included tests of impulse control, sensation-seeking, resistance to peer influence, future orientation and risk perception. The cognitive battery included measures of basic intellectual abilities.

There were no differences among the youngest four age groups (10-11, 12-13, 14-15 and 16-17) on the measures of psychosocial maturity. But significant differences in maturity, favoring adults, were found between the 16- to 17-year-olds and those 22 years and older, and between the 18- to 21-year-olds and those 26 and older. Results were the same for males and females, the authors said.

“It is very difficult for a 16-year-old to resist peer pressure in a heated, volatile situation,” Steinberg said. “Most times, there is no time to talk to an adult to inject some reason and reality to the situation. Many crimes committed by adolescents are done in groups with other teens and are not premeditated.”

In contrast, differences in cognitive capacity measures increased from ages 11 to 16 and then showed no improvements after age 16 – exactly the opposite of the pattern found on the psychosocial measures. Certain cognitive abilities, such as the ability to reason logically, reach adult levels long before psychosocial maturity is attained, Steinberg said.

“Medical decisions are those where adolescents can take the time to understand and weigh options provided by health care practitioners,” said Steinberg. “Rarely are these decisions made in the heat of the moment without consultation with adults. Under these circumstances, adolescents exhibit adult maturity.”

Two friend-of-the-court briefs filed by APA in cases heard by the Supreme Court spurred questions about these maturity differences and the apparent inconsistency between APA’s positions in the two cases. In its amicus brief filed in Roper v. Simmons (2005), the case that abolished the juvenile death penalty, APA presented research showing that adolescents are developmentally immature in ways that are relevant to their criminal culpability. In an earlier brief filed in Hodgson v. Minnesota (1990), which upheld adolescents’ right to seek an abortion without parental approval, APA presented research regarding cognitive abilities that bear on medical choices, showing that adolescents are as mature as adults.

APA differentiated these two scenarios by looking at the decision-making processes required for each situation. In the Hodgson case, APA described adolescents as being competent to make informed and sound health care decisions. In the Roper case, APA characterized adolescents as too short-sighted and impulsive to warrant capital punishment, no matter what the crime. APA placed the research about psychosocial development of adolescents in the context of a court’s need to determine as part of a death penalty sentence that the perpetrator can reliably be assessed as among the “worst of the worst.”

In November, the Supreme Court is slated to hear two cases concerning the constitutionality of sentencing juveniles to life without the possibility of parole. “Similar questions about adolescent development may be raised in these cases,” Steinberg said. APA has filed an amicus curiae brief in those cases presenting relevant research, including Steinberg’s most recent study, to the court.

Adolescents’ legal rights, said Steinberg, should be guided by accurate and timely scientific evidence on the nature and course of psychological development. “It is crucial to understand that brain systems responsible for logical reasoning and basic information processing mature earlier than systems responsible for self-regulation and the coordination of emotion and thinking,” he said.

---

Journal reference:

1. Laurence Steinberg, Elizabeth Cauffman, Jennifer Woolard, Sandra Graham, Marie Banich. Are Adolescents Less Mature than Adults? Minors’ Access to Abortion, the Juvenile Death Penalty, and the Alleged APA ‘Flip-Flop’. American Psychologist, 2009; Vol. 64, No. 7 DOI: 10.1037/a0014763