Adults have rich beliefs about children's development timelines, and they interpret and react to children's behaviors across ages, holding children responsible to some degree. While children's mental capacity and potential could motivate moral agency attribution, a question remains whether a consistent relation exists between the empirical beliefs about children's various capacities and the responsibility attribution to their behaviors that manifest the corresponding capacities. Here, we tested 361 adults (UK, US) on their folk psychology and moral beliefs about different ages with vignettes that reflect agential control in various domains (motor control, inhibitory control, theory of mind, planning, moral evaluation) combined with several variants of scenarios. We characterized the relation between adults' expectations and responsibility attribution with mixed models. We found that this moral reasoning varies for targets of different ages and the amount of responsibility is mostly determined by age. We suggest an alternative mechanism between capacity- and moral beliefs.