From the paper: > a widely used and validated mental-health screening tool (i.e., > the Strengths and Difficulties Questionnaire or SDQ). The SDQ was

From the paper: > a widely used and validated mental-health screening tool (i.e., > the Strengths and Difficulties Questionnaire or SDQ). The SDQ was > was explicitly designed for children and generates measures of > several distinct psychopathological constructs, some of which > are clearly related to the theorized effects of delayed school > starts. > we find that these effects are largely driven by a large > reduction (effect size = -0.70) in a single SDQ construct: the > SDQ’s inattention / hyperactivity score (i.e., a mea-sure of self > regulation).