According to Science Daily it seems that one really can judge a book by its cover.
A study in the current issue of Personality and Social Psychology Bulletin (PSBP), the official monthly journal of the Society for Personality and Social Psychology indicates that subjects were able to accurately judge some aspects of a stranger's personality from looking at photographs
Researchers asked participants to assess the personalities of strangers based first on a photograph posed to the researchers' specifications and then on a photograph posed the way the subject chose. Those judgments were then compared with how the person and acquaintances rated that individual's personality. They found that while both poses provided participants with accurate cues about personality, the spontaneous pose showed more insight, including about the subject's agreeableness, emotional stability, openness, likability, and loneliness.
"As we predicted, physical appearance serves as a channel through which personality is manifested," stated the authors. "By using full-body photographs and examining a broad range of traits, we identified domains of accuracy that have been overlooked, leading to the conclusion that physical appearance may play a more important role in personality judgment than previously thought."
Well I never! Perhaps you can but first impression do often lie. I know that to my cost.
SAGE Publications (2009, December 11). Personalities accurately judged by physical appearance alone. Science Daily. Retrieved