The original hypothesis of "Seven Up!" was that class structure is so strong in the UK that a person's life path would be set at birth. The producer of the original programme had at one point thought to line the children up on the street, have three of them step forward and narrate "of these twenty children, only three will be successful" (an idea which was not used). The idea of class immobility held up in most, but not all, cases as the series has progressed. The children from the working classes have by and large remained in those circles, though Tony seems to have become more middle class. Apted has said that one of his regrets is that they did not take feminism into account, and consequently had fewer girls in their study and did not select them on the basis of any possible careers they might choose.