Complex lying leads to more memory impairments in daily life

Previous
studies have demonstrated that lying can undermine memory and that its memory-undermining
effects could be modulated by the cognitive resources required to tell a lie.
We extended the investigation of the memory-undermining effect by using a daily
life setting in which participants were highly involved in a mock shopping
task. Participants were randomly assigned to truth-telling, simple lying or
complex lying conditions. After finishing the shopping task, participants were
told that two people wanted to know about their shopping lists and would ask them
some questions in an interview. In answering the interview questions, the truth-telling
group was asked to respond honestly, the simple lying group was asked to give denial responses, and the complex lying group was
required to respond deceptively. The item memory test, source memory test and
destination memory test were given in an orderly manner 48 hours after the
interview. We found that the complex lying group, rather than the simple lying group,
forgot the lies they told in the interview and mistakenly believed they had
lied about something that they had not lied about. Moreover, the complex lying
group retained fewer memories about the person they responded to than the honest
group. In addition, participants in the complex lying group had more nonbelieved
memories than those in the truth-telling group in both item and source memory tests.
We conclude that complex lying that requires more cognitive resources could
result in more memory impairments in daily life.