The child objection is a major challenge for reductionism, which requires hearers to have positive reasons for testimonial justification. However, it has been pointed out that anti-reductionism, which requires only the absence of negative reasons, or defeaters, suffers from the same kind of problem. The child objection presupposes the empirical thesis that “children do not have the capacity to consider reasons,” but the plausibility of this assumption may be revealed by developmental psychology research on selective trust. This paper uses recent epistemological studies as a guide to narrow down the types of defeaters that children are required to consider, and then clarifies what kind of reasons various experiments can be said to test the ability to consider, and in what sense children who pass the test can be said to be “considering” reasons. In doing so, we clarify the scope and limits of the implications that selective trust studies can have for reductionism and anti-reductionism. We then suggest what future psychological research is desired from an epistemological interest to go beyond the current limitations.