The relationship between psychopathy tendency and practice effect on face recognition deception

Abstract

Deception is a common human behaviour, and the majority of previous behavioural studies have used factual statements as the stimuli to study deceptive behaviour. Facial recognition is a daily experience that people may lie about, yet there has been scant research on facial recognition deception. Moreover, previous studies suggested that practice effect and psychopathic tendency might affect people’s performance on a lying task.

The present research aimed to fill this research gap by examining the relationships between psychopathic tendency, practice effects and facial recognition deception using a directed-lying task.

Two hundred and twenty-three Chinese participants were recruited through the University and their psychopathic tendency was measured. Twenty-one participants with relatively low and 19 participants with relatively high psychopathic tendency were invited to participate in the experiment, which was divided into four phases (i.e. the time factor): Baseline, Training 1, Training 2 and Testing. In each trial, the participants were presented with personally familiar or unfamiliar faces (i.e. the familiarity factor) through a directedlying task in which they either had to tell the truth or lie (i.e. the response factor) in accordance with the instructions. Their reaction times and response accuracy in performing the task were recorded in all of the phases.

The results showed that both reaction time and response accuracy differentiated the level of face familiarity encountered by the participants. The reaction time also revealed whether the participants were telling the truth or lying. There was a significant interaction between the response and familiarity factors. Lying was found to increase the reaction time for familiar faces more than for unfamiliar faces. The interaction effects between the response, familiarity and psychopathic tendency factors were also significant. Lying lengthened the reaction time for familiar faces in the low psychopathic tendency group, but not in the high psychopathic tendency group. For familiar faces, the interaction effect between the response and time factors was significant. The reduction in the reaction time for lying was significantly greater than that for telling the truth across the phases, yet the reaction time for telling the truth was still shorter than that for lying to the familiar faces in the testing phase. The above effects were obtained after controlling for differences in perceived emotion intensity and attractiveness between familiar and unfamiliar faces.

Generally, the practice effect was observed as the reaction time was reduced. It was also found that people with high and low psychopathic tendency performed differently on a directed-lying task on face familiarity, as indicated by reaction time. The results are discussed in relation to information processing and deception detection.