Amidst public anxiety over any number of threats to British interests, Michael Blastland turns the lens of psychology from 'us' to 'them', and perceptions of 'the other'. From sports teams to supermarkets, politics to religion, we define ourselves partly by the other. And with the news full of fear of terrorist attacks, talk of war and immigration, the question of how we perceive groups outside our own is increasingly relevant. How do we see 'them', whoever they are? Are we naturally fearful of those who aren't like us? What is the morality of otherness? Can our categorising of the other lead to a potential for racism? Michael Blastland investigates with resident Zoo psychologist Nick Chater, Professor of Behavioural Science at Warwick Business School, and roving reporter Timandra Harkness. Contributors this week include sports commentator Alison Mitchell on otherness in cricket, and comedian Simon Evans on its function in standup. Producer: Eve Streeter A Pier production for BBC Radio 4.