Theory of Mind in adults: Deception detection and reading facial expressions in the normal and autistic population

Theory of Mind (ToM) is an intuitive skill allowing an individual to consider other’s thoughts, feelings and behaviours, and is vital in the context of complex interactions and group living. It comes naturally to most, but is difficult to grasp for those with autism spectrum disorder. The ability to read facial expressions and detect deception in normal and autistic adults was investigated by asking 788 participants to complete the Autism Quotient Test, the Reading the Mind in the Eyes Test (RMET), and a Jokes and Lies Test. For the RMET, participants were instructed to identify the emotion or feeling expressed by eyes presented in a photograph, and the Jokes and Lies Test required the participants to answer ToM questions about different deceptive scenarios. Results indicated that the majority of the normal participants scored above average on the RMET, whilst the Jokes and Lies Test proved to be very difficult for a significant proportion as 45% of the participants answered the questions incorrectly. The data suggested a significant improvement in ToM deception detection abilities in the participants over the age of 35, supporting the ‘with age comes wisdom’ theory. The participants deemed as ‘autistic’ (due to their clinical diagnosis or their AQ score) performed significantly worse than the normal participants on the RMET (although not on the Jokes and Lies test). No gender differences, nor gender x diagnosis interaction were apparent. These findings suggest that certain ToM tasks in the normal adult population are not as well developed as past research has suggested and that given the large sample used, the AQ is a valid measure within an Australian population