Relationships among age, socioeconomic status, and distractibility in preschoolers as assessed by the Competitive Attention Test

•The Competitive Attention Test, is suitable for characterizing distractibility in children as young as four.•Task-irrelevant distractors induced distraction, phasic arousal, and impulsivity in four- and five-year-olds.•Sustained attention, as assessed by the Competitive Attention Test, improved with age.•Children from lower socioeconomic backgrounds showed reduced sustained attention and greater impulsivity.