German-learning infants recognize common nouns without additional frequency cues

The success of infants in fixating on a named target when they see it together with a distracting stimulus in the "looking while listening" (LWL) paradigm varies between studies using different stimulus material, participants, and target languages. This calls for systematic investigation of aspects that could influence infants' LWL performance. In this preregistered online study, we tested the hypothesis that an imbalance in word frequency between target and distractor words could help young infants match more frequently heard words with presumably more frequent referents. We tested 80 German-learning infants aged 6-24 months, divided into a younger group (6-14 months, n = 43) and an older group (15-24 months, n = 37). We systematically manipulated frequency imbalance within target-distractor pairs and found evidence of successful target fixations in both groups. The preregistered analysis of younger children's data revealed no differences for the same targets presented in imbalanced versus balanced pairs. This suggests that infants did not rely on frequency cues to distinguish between target and distractor objects, and that early noun-object associations are semantically more robust than previously assumed. We discuss limitations of the results due to variations in trial duration and word frequency estimation.