What can you tell about someone by looking at their signature?
142 second year university students from both Memorial University of Newfoundland (n = 81) and Laurentian University (n = 61) wrote their own signatures as they imagined the following people would do: (a) faculty member (high status) with high self-esteem, (b) faculty member (high status) with low self-esteem, (c) student (low status) with high self-esteem, and (d) student (low status) with low self-esteem. The areas of the signatures were calculated in square centimeters, and there was a significant positive relationship between size of signature and the conditions of high and low self-esteem for both “faculty” and “student” role-playing conditions. There was however no significant relationship between size of signature and status. The results held for both groups of subjects.
Source: “Effects of self-esteem and status on size of signature.” from Percept Mot Skills. 1977 Feb;44(1):185-6.
This is another great study I found in Robert Cialdini’s fantastic book, Influence.
I also recommend his more recent release Yes!: 50 Scientifically Proven Ways to Be Persuasive.