An arguable strength of ethics standards that are not codified into law, is that they allow a more project-specific and nuanced approach to ethical challenges.  This includes the approach to assent when the potential participants are toddlers or infants.  An argument could be made that frameworks like those in the US do allow research ethics committees to issue thoughtful review feedback but experience suggests they don’t always do so.  How does your local research ethics committee approach consent from young children?