AbstractCurrent debate has identified the factors emotion knowledge (EK) and attention as specific trajectories longitudinally influencing psychopathological development in childhood. The “Emotion Knowledge Hypothesis” assumes that children with great emotion skills have high self-regulating abilities that result in lower cognitive load and stronger attention capacities. Attention problems are thus perceived as a consequence of reduced EK. According to the competing “Attention Effect Hypothesis”, attention problems and EK deficits are associated because of impaired learning capacities due to attention problems. According to this hypothesis, attention problems are predictive of impaired EK. If those specific trajectories are disrupted, this might attenuate the development of later behavior problems. The present study tests those competing hypotheses replicating previous studies in this field to shed light on potential psychopathology trajectories. A total of 136 pre- and elementary school children as well as their teachers participated in this study. Children’s symptoms of inattention as well as their emotional competences were assessed 3 times over a 12-month period. We applied multilevel structural equation modelling and cross-lagged panel models for data analysis. Overall, we noted a drop in inattention scores and rise in emotional competences over the one-year course, indicating maturation effects. There was a significant but very small effect for attention scores predicting emotional competences. With respect to the question whether interventions should focus on the “Emotion Knowledge” or “Attention Effect” hypothesis, our findings imply that none of them has superiority over the other. Therefore, both emotion knowledge and attention are crucial for development, and that children with deficits in either domain should receive targeted interventions in order to disrupt potentially harmful developmental pathways.