Psychology expert Dr Rachael Molitor says the ability to become sociable has been a key trait to becoming a successful traitor in the hit BBC reality show The Traitors, ahead of the season finale on Friday 26 January.In the second series, airing now, Traitors Harry and Andrew have so far proved elusive - with the Faithful struggling to identify who should and should not be trusted."What makes a good Traitor is the ability to become sociable, to be able to make friends," Dr Molitor said. "Harry has always been acting as a Faithful the whole time and people are on his side, fighting for him."