The researchers are arguing that using ECG reduces subjectivity in personality assessment. Which is predominantly determined by self reported questionnaires.

They are mapping ECG data to the 'big 5' personality traits, and neglected to mention how these traits were determined for each participant prior to measuring the model's predictive accuracy. Almost certainly these primary trait scores were determined through a questionnaire.

Does this have any more validity than the E-meter from Scientology?

From the paper:

>Traditionally, assessment for personality traits has relied heavily on self-reported questionnaires and behavioral observations. While these methods have proven valuable, they also introduce subjectivity and potential biases