article_snippet.sent: Civilisations move in 'cycles' dependent on factors such as food supply, religion and conflict, while epigenetics - a field of study within DNA - explains how people's attitudes and temperament change over time and thus shape society, Dr Penman, of the RMIT University in Melbourne argues. '
article_snippet.sent: The First World War had an epigenetic effect in that mothers made anxious by The First World War gave birth to an unusually aggressive generation which was the main cause of the Second World War', Dr Penman, of the RMIT University in Melbourne writes. '
highlights_snippet.sent: Adaption of genes means we are less aggressive or likely to go to war .