The operation of confirmation bias : discourse analysis of witnesses' evidence about the conduct of a sexual abuser : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Psychology at Massey University, Palmerston North, New Zealand

Confirmation bias is a cognitive bias where beliefs formed at an early stage are unreasonably sustained even in the face of new information that makes those beliefs untenable or at least questionable. In these circumstances, new information that does not fit with the earlier-formed beliefs may be ignored, while information supporting those beliefs is accepted readily as lending credence to them. During 2010 and 2011, Jonathan Lord was employed by the YMCA in New South Wales, Australia, until a child disclosed that he had been inappropriate touched by Mr Lord. This led to Mr Lord being convicted of 13 representative offences including multiple aggravated indecent assault charges and two counts of sexual intercourse with a child under 10, relating to 12 children enrolled in the YMCA Before and After School Care service. Subsequently, several of the children's parents, and some of Mr Lord's YMCA co-workers, gave evidence to the Royal Commission into Institutional Responses to Child Sexual Abuse that was conducted in Australia from 2012 to 2017. This study shows how confirmation bias may lead to tragic or destructive outcomes in some circumstances. The use of discourse analysis in this study has afforded a 'micro context' understanding of how Mr Lord's abuse of children associated with the YMCA service persisted undetected for more than a year, despite Mr Lord breaching YMCA rules and being observed engaging in other questionable conduct regarding children in that period