Phonological awareness and sex in early literacy: no detectable sex differences in a digital game-based battery in Brazilian Portuguese

Phonological awareness (PA) is one of the strongest predictors of reading and writing acquisition. Small female advantages have been reported in related verbal domains — chiefly in tasks whose response modality involves oral production — but evidence directly assessing sex differences in PA itself is scarce. This study examined whether sex differences would emerge in a seven-game digital battery (JILEC-1), answered exclusively through touchscreen selection with no oral production, administered to 632 Brazilian children (328 girls; 304 boys) from Kindergarten to Grade 2 — speakers of Brazilian Portuguese, an orthography of intermediate depth. Using Welch’s t tests with Holm correction, no significant differences were observed on any of the seven games or on the composite score (Game Progress Index, GPI; d = 0.035–0.124; minimum detectable d = 0.22; upper bound of the 95% CI for the overall index: d = 0.23). The pattern did not vary across grades (Sex × Grade interaction: p = .313) or schools ( p = .949), and held for an index restricted to the five PA-proper games. Exploratory component analyses revealed opposing, mutually cancelling profiles: girls were slightly more accurate (d = 0.103) and boys slightly faster (d = − 0.035). In hierarchical regression, sex contributed a partial R² of 0.6%, whereas school grade explained 49% of the variance, with the largest gain at the transition into Grade 1 (d = 1.47). Combined with the full scalar measurement invariance across sex documented for the battery, the results provide initial evidence of sex-equitable measurement in this format and position assessment format as a hypothesis to be tested in direct format comparisons.