Acoustic/Prosodic and Lexical Correlates of Charismatic Speech

1. Acoustic/Prosodic and Lexical Correlates of Charismatic Speech Andrew Rosenberg & Julia Hirschberg Columbia University 10/10/05 - IBM

2. Why study charismatic speech? • Construction of a feedback system for public speakers, (politicians, academic instructors, etc.) • Identification of potential charismatic leaders • Automatic generation of “charismatic-like” speech

3. What is charisma? • Not face-to-face, one-on-one charisma. • Rather, public (political, religious,etc.) charisma • The ability to attract, and retain followers by virtue of personality as opposed to tradition or laws. (Weber ‘47) • E.g. Ghandi, Hitler, Castro. • Charismatic speech: Speech that leads listeners to perceive the speaker as “charismatic”.

4. Goals of this study • Do people agree on what kind of speech is charismatic? • Is there a common, functional definition of charisma? • What acoustic/prosodic and lexical properties of speech communicate charisma?

5. Study Description • Format: web survey • Subjects: 8, solicited via email, no monetary incentive • Dependent variables: 5-point Likert scale ratings of agreement on 26 statements about the speaker. • Duration: avg. 1.5 hrs, min 45m, max ~3hrs

6. Study Description • Materials: 45 short (2-30s) tokens of American political speech from late ’03 and early ‘04 • Speakers: 9 Candidates for Democratic Party’s nomination for President • Wesley Clark, Howard Dean, John Edwards, Dick Gephardt, John Kerry, Dennis Kucinich, Joseph Lieberman, Carol Moseley Braun, Al Sharpton • Topics: Postwar Iraq, Healthcare, Bush’s Tax plan, Reason for Running, Content-Neutral

7. How much do subjects agree with one another? • Using the weighted kappa statistic with quadratic weighting, mean  = 0.213 • Do subjects agree about what is charismatic? •  = 0.224 (8th) • Inter-subject agreement by token • No significant differences across all tokens • Inter-subject agreement by statement • The individual statements demonstrate significantly different agreements

8. What do subjects mean by “charismatic”? • Which pairs of statements were most closely correlated with the charismatic statement, determined by kappa.

9. Does the identity of the speaker affect judgments of charisma? • There is a significant difference between speakers (p=1.75e-2) • Most charismatic • Rep. Edwards (3.73) • Rev. Sharpton (3.40) • Gov. Dean (3.32) • Least charismatic • Sen. Lieberman (2.38) • Rep. Kucinich (2.73) • Rep. Gephardt (2.77)

10. Does recognizing a speaker affect judgments of charisma? • Subjects were asked to identify which, if any, speakers they recognized at the end of the study. • Subjects rated recognized speakers (3.28) significantly more charismatic than those they did not (2.99).

11. Does the genre or topic of speech affect judgments of charisma? • The tokens were taken from debates, interviews, stump speeches, and a campaign ad • Stump speeches were the most charismatic. (3.28) • Interviews the least. (2.90) • Topic does not affect ratings of charisma.

12. Duration (secs) Min, max, mean, stdev F0 Raw and normalized by speaker Min, max, mean, stdev intensity Speaking rate (syls/sec) Length (words, syls) 1st, 2nd, 3rd person pronoun density Function to content word ratio Mean syllables/word Mean words per intermediate and intonational phrase Number of intonational, intermediate, and internal phrases Mean and stdev of normalized F0 and intensity across phrases Require manual labeling of phrase boundaries What makes speech charismatic?Acoustic/Prosodic and Lexical Properties Examined

13. What makes speech charismatic?Properties showing positive correlation with charisma • More Content • Length in secs, words, syllables, and phrases • Higher and more dynamic raw F0 • Min, max, mean, std. dev. of F0 over male speakers • Greater intensity • Mean intensity • Higher in a speaker’s pitch range • Mean normalized F0

14. What makes speech charismatic?Properties showing positive correlation with charisma • Faster speaking rate • Syllables per second • Greater variation of F0 and intensity across phrases • Std. dev. of normalized phrase F0 and intensity • The use of more first person pronouns • First person pronoun density • The use of polysyllabic words • Lexical complexity (mean syllables per word)

15. Conclusions • There are substantial individual differences in subject perception of charisma. • Subjects seem to agree on a common, functional definition of charisma. • “A charismatic speaker is enthusiastic, charming, convincing, persuasive, powerful and not boring” • Broadly, dynamic speech – loud, high in the pitch range – using first person pronouns is associated with charisma.

16. Future Research • Isolate the lexical component of speech to determine the relative influences of what is said and how it is said. • Modify acoustic/prosodic features to resynthesize more/less charismatic speech • Study communication of charisma in other languages, specifically Palestinian Arabic.