Connal's doctoral thesis on Ulster Protestant working class politics and culture since 1960 viewed political developments and political and social history through the prism of dramatists and writers from this background. This was the basis of his first book Inventing the Myth: Political Passions and the Ulster Protestant Imagination (Oxford University Press, 2017). The book was shortlisted for the Ewart-Biggs Literary Prize (for titles 2015-17) and the Royal Historical Society's Whitfield Prize for distinguished first books. It was also the basis of a three-month series funded by the International Fund for Ireland entitled 'Across the Lines', which took place in two border counties of Ireland in the autumn of 2019. It engaged civilians from border counties and discussed Ulster Protestant, Unionist and Loyalist identity.

His present research builds on his expertise in Northern Ireland to comparatively explore how states such as South Africa, Spain, Chile and others deal with a divided and violent past. It illustrates how the arts and culture resonate with a transitional justice element, playing an active role in conflict transformation and peace-building across the world. He is currently finishing his second book on the Irish Anti-Apartheid Movement.