The issue focused on two primary factors - whether sex differences are growing and whether there are negative consequences for children's lives. At the heart of the debate was whether sex differences are becoming less visible in society.On one side was the UN's Human Development Report which noted that sex differences were growing in almost every society in the world. On the other side were groups such as the French Centre for Population Research who argued that sex differences were changing but were still seen as extremely rare. One group - the Research Network for Sex