The aim of this study was to investigate people?s ability to detect deception and if variables such as birth order, personality and suspiciousness affect this ability. The study was conducted at Växjö University with students as participants (n = 278). A film of two people arguing both for and against their own personal opinions was constructed and participants assessed credibility on a categorical scale (Honest/Dishonest). Neither birth order nor level of suspiciousness revealed significant differences as pertains to credibility attribution.