- Intelligence is of utmost importance in many areas of life.
Measures of intelligence predict adjustment in academic, professional, and clinical settings and provide valid indicators of cognitive development and aging.
Thus, measuring intelligence as accurately as possible in all populations is crucial.
To do so, we need to know whether the structural organization of different cognitive abilities within structure-of-intelligence models is equivalent across ability and age groups.
Differentiation hypotheses of intelligence describe changes in the relationship between different cognitive abilities (i.e., their structural organization) depending on the level of general ability (ability differentiation), age (differentiation in children and adolescents; dedifferentiation in older adults), and their interaction.
We present a systematic review of methodologically sound studies that examined differentiation effects.
In total, 33 reports with data from 51 studies and 264,300 participants were included. The results predominantlyIntelligence is of utmost importance in many areas of life.
Measures of intelligence predict adjustment in academic, professional, and clinical settings and provide valid indicators of cognitive development and aging.
Thus, measuring intelligence as accurately as possible in all populations is crucial.
To do so, we need to know whether the structural organization of different cognitive abilities within structure-of-intelligence models is equivalent across ability and age groups.
Differentiation hypotheses of intelligence describe changes in the relationship between different cognitive abilities (i.e., their structural organization) depending on the level of general ability (ability differentiation), age (differentiation in children and adolescents; dedifferentiation in older adults), and their interaction.
We present a systematic review of methodologically sound studies that examined differentiation effects.
In total, 33 reports with data from 51 studies and 264,300 participants were included. The results predominantly supported ability differentiation in children and adults, and age dedifferentiation in older adults, with effect sizes that implicate a practical significance of the effects.
Age differentiation in children and adolescents was not supported. Instead, there was some evidence for age dedifferentiation in adolescents, but with negligible effect sizes. A small number of studies with children and adolescents found interaction effects in which ability differentiation increased with age.
We describe implications and directions for future research, involving multimethod studies, method development, and individual participant data meta-analysis.…
