The age of maturity of children to consent for medical research is und
er debate, as different authorities regard the capacity of young teena
gers as either satisfactory or not to grant consent without parental p
articipation in the process. The present paper contrasts the generally
accepted guideline for ethics in paediatric research in Canada with w
hat the same children are allowed and expected to be able to do as bab
ysitters. This comparison reveals deep incongruences in the way the ma
turity of the same children is appreciated for two different tasks.