This article presents the results of a study conducted as part of a collaboration between researchers from the Unit of Applied Neurobiology (CEMIC-CONICET) and the Chronobiology Laboratory at the National University of Quilmes.

Interval timing refers to the ability of the brain to perceive and measure the duration of time in the seconds-to-minute range. Young children’s time judgments are significantly more variable than adults’, associated with different factors (e.g., age, hormones, chronotype, and cognition). Despite this, little is known regarding the modulation of time estimation in children younger than five. In this study we explore time estimation in 4-year-old children and its modulation by individual (i.e., sex and temperament) and socio-environmental factors (i.e., socioeconomic status, SES). One hundred twenty-one children completed a time reproduction task with three stimuli durations (2s, 3s, and 4s). Parents reported on the child’s SES and temperament (data was collected in 2016–2017). Results indicate that mean reproduction time was significantly different between SES for the 4 s interval. Also, timing performance varied by child sex across all evaluated variables, except for the score in the 4s interval, with girls achieving higher scores than boys. Finally, significant differences were verified according to child temperament and SES. Specifically, higher scores in the 2 s interval were obtained for children with higher effortful control. Furthermore, the distribution of temperament groups was similar across SES conditions, except for surgency, where more cases with unsatisfied basic needs were observed in the low surgency group. In sum, the results of this study present evidence of the importance of considering individual characteristics (i.e., temperament and sex) in the study of time estimation since they would provide possible sources of variation in children’s performances, even beyond the SES conditions.