Associations between myside bias on an informal reasoning task and amount of post-secondary education

One hundred and twelve undergraduate university students completed an informal reasoning task in which they were asked to generate arguments both for and against the position they endorsed on three separate issues. Performance on this task was evaluated by comparing the number of arguments they generated which endorsed (myside arguments) and which refuted (otherside arguments) their own position on that issue. Participants generated more myside arguments than otherside arguments on all three issues, thus consistently showing a myside bias effect on each issue. Differences in cognitive ability were not associated with individual differences in myside bias. However, year in university was a significant predictor of myside bias. The degree of myside bias decreased systematically with year in university. Year in university remained a significant predictor of myside bias even when both cognitive ability and age were statistically partialled out. Copyright (C) 2003 John Wiley Sons, Ltd.