Rational thinking in children and adolescents improves with age and positively correlates with intelligence and executive functioning, according to the findings of a five-year study led by a York researcher.
Rational thinking has been studied in adults, but relatively less work has been done to test its development in children. It is broadly defined as how well people accomplish their goals and track truth in the world. The researchers, York psychology Professor Maggie Toplak, along with Richard West of James Madison University and Keith Stanovich of the 
University of Toronto, modified some of the adult tests to make them appropriate for children.
Maggie Toplak
“The results are very exciting. Scientifically, they are consistent with what we are finding in our adult work,” says Toplak. “But also, it’s a major step in developing new ways to examine competence in youth, beyond the current obsession with measures of intelligence and executive functions.”
Their research is highlighted in the article, “Rational Thinking and Cognitive Sophistication: Development, Cognitive Ability, and Thinking Dispositions”, co-authored by Toplak, West and Stanovich and published in the November issue of the journal of Developmental Psychology.
This research could affect how competence is assessed in youth, taking not only intelligence and executive functions into consideration, but using rational thinking and decision-making as indicators of competence.
“These measures can help us understand judgments related to youth risk and issues of legal responsibility,” says Toplak. “In our increasingly complex technological society, it will be fundamental to assess these competencies and to teach our children how and when to make careful judgments and choices.” The research could lead to several potential implications and directions for this work. In the lab at York, Toplak and her team have also examined using rational thinking to assess competence in pathological gamblers and offending youth.
In the study, the researchers looked at developmental trends in five reasoning tasks considered critical components of rational thinking in 204 students from grades two to nine, breaking them into three groups (Grades 2 to 3, 4 to 5 and 6 to 9).
With the rational thinking research with children and youth, “our strategy was to examine converging evidence. If there was evidence that older children do better than younger children on some of these tasks, then performance on these tasks should also be correlated with cognitive abilities, such as intelligence and executive functions, and dispositions related to open minded thinking,” says Toplak. “Indeed, this is what we did.”
It’s not a new question – do children get better at rational thinking as they age and develop – but it has sparked intense debate in the psychological literature, says Toplak. “There are two very different arguments. One says, of course, cognition gets better. The other side says no. Biases are introduced and reinforced and if adults make rational thinking errors, so too will children fail to recognize the situations that call for more considered reasoning as they get older.”
Under cognitive ability measures, the researchers tested verbal and non-verbal intelligence and executive functions. Thinking dispositions included the actively open minded thinking scale, the superstitious thinking scale and the need for cognition scale. As for rational thinking task, they studied denominator neglect, belief bias syllogism, resistance to framing, base rate sensitivity, other side thinking, and asked parents to rate their child’s decision making ability.
The research was supported through a Social Sciences & Humanities Council of Canada (SSHRC) Operating Grant to Toplak, who was recently awarded a by SSHRC Insight Grant to continue the research. “The Development of Rational Thinking Abilities: Longitudinal Change and Real World Outcomes” will involve a five-year longitudinal study of children and adolescents to determine if these measures of rational thinking predict outcomes in these youth.
By Sandra McLean, YFile deputy editor