Paul Cohen-Portheim claimed that 'religion played an astonishingly small part in the men's life' although he did point to the availability of services. Within the concentration camps the most obvious manifestation of religion, apart from the holding of services, consisted of the celebrations of the major religious festivals which remained the most important day in the calendar. Despite the development of barbed wire disease and the feelings of isolation which some internees felt, the vast majority participated in the educational, social and cultural activity which developed in the camps. This took a variety of forms, including religion; reading, writing and learning; high culture; and sport. In some camps the majority of prisoners found little useful employment, which meant that they had to develop other ways of passing their time. This led to the evolution of 'prison camp societies', to use John Davidson Ketchum's phrase.