Charisma in English and Arabic Political Speech

Julia Hirschberg

Columbia UniversityJoint work with Andrew Rosenberg and

Fadi Biadsy

Stony Brook University, 9 Nov 2007

What is Charisma?

• The ability to attract, and retain followers by virtue of personal characteristics -- not traditional or political office (Weber ‘47)– E.g. Gandhi, Hitler, Castro, Martin Luther King Jr.,..– Personalismo

• What makes an individual charismatic? (Bird ’93, Boss ’76, Dowis ’00, Marcus ’67, Touati ’93, Tuppen ’74, Weber ‘47)– Their message?– Their personality?– Their speaking style?

What is Charismatic Speech?

• Circularly…– Speech that leads listeners to perceive the speaker as

charismatic

• What aspects of speech might contribute to the perception of a speaker as charismatic?– Content of the message?

– Lexico-syntactic features?

– Acoustic-prosodic features?

Why Study Charismatic Speech?

• It’s an interesting phenomenon• To identify potential charismatic leaders• To provide a feedback system for individuals who

want to improve their speaking style -- politicians, professors, students…

• To create a charismatic Text-to-Speech system

Our Approach

• Collect tokens of charismatic and non-charismatic speech from a small set of speakers on a small set of topics

• Ask listeners to rate the ‘The speaker is charismatic’ plus statements about a number of other attributes (e.g. The speaker is …boring, charming, persuasive,…)

• Correlate listener ratings with lexico-syntactic and acoustic-prosodic features of the tokens to identify potential cues to perception of charisma

American English Perception Study

• Data: 45 2-30s speech segments, 5 each from 9 candidates for Democratic nomination for U.S. president in 2004– 2 ‘charismatic’, 2 ‘not charismatic’

– Topics: greeting, reasons for running, tax cuts, postwar Iraq, healthcare

– 4 genres: stump speeches, debates, interviews, ads

• 8 subjects rated each segment on a Likert scale (1-5) for 26 questions in a web survey

• Duration: avg. 1.5 hrs, min 45m, max ~3hrs

Results: How Much Do Subjects Agree with Each Other?

• Over all statements?– Using weighted kappa statistic with quadratic weighting, mean =

0.207

• On the charismatic statement? = 0.232 (8th most agreed upon statement)

• By token?– No significant differences across all tokens

• By statement?– Individual statements demonstrate significantly different

agreements (most agreement: The speaker is accusatory, angry, passionate, intense; least agreement: The speaker is trustworthy, believable, reasonable, trustworthy)

Results: What Do Subjects Mean by Charismatic?

• Which other statements are most closely correlated with the charismatic statement? (determined by kappa): a functional definition

The speaker is enthusiastic 0.620

The speaker is persuasive 0.577

The speaker is charming 0.575

The speaker is passionate 0.543

The speaker is boring -0.513

The speaker is convincing 0.499

Results: Does Whether a Subject Agrees with the Speaker or Finds the Speaker ‘Clear’ Affect

Charisma Judgments

• Whether a subject agrees with a token does not correlate highly with charisma judgments ( = 0.30)

• Whether a subject finds the token clear does not correlate highly with charisma judgments ( = 0.26)

Results: Does the Identity of the Speaker Affect Judgments of Charisma?

• There is a significant difference between speakers (p=2.20e-2)

• Most charismatic – Rep. John Edwards (mean 3.86)– Rev. Al Sharpton (3.56)– Gov. Howard Dean (3.40)

• Least charismatic– Sen. Joseph Lieberman (2.42)– Rep. Dennis Kucinich (2.65)– Rep. Richard Gephardt (2.93)

Results: Does Recognizing a Speaker Affect Judgments of Charisma?

• Subjects asked to identify which, if any, speakers they recognized at the end of the study.

• Mean number of speakers believed to have been recognized, 5.8

• Subjects rated ‘recognized’ speakers as significantly more charismatic than those they did not (mean 3.39 vs. mean 3.30).

Results: Does Genre or Topic Affect Judgments of Charisma?

• Recall that tokens were taken from debates, interviews, stump speeches, and campaign ads– Genre does influence charisma ratings (p=.0004)

– Stump speeches were the most charismatic (3.38)

– Interviews were the least (2.96)

• Topic does affect ratings of charisma significantly (p=.0517) – Healthcare > post-war Iraq > reasons for running

neutral > taxes

What makes Speech Charismatic?Features Examined

• Duration (secs, words, syls)

• Charismatic speech is personal: Pronoun density

• Charismatic speech is contentful: Function/content word ratio

• Charismatic speech is simple: Complexity: mean syllables/word (Dowis)

• Disfluencies

• Repeated words

• Min, max, mean, stdev F0 (Boss, Tuppen)– Raw and normalized by

speaker• Min, max, mean, stdev

intensity• Speaking rate (syls/sec)• Intonational features:

– Pitch accents– Phrasal tones– Contours

Results: Lexico-Syntactic Correlates of Charisma

• Length: Greater number of words positively correlates with charisma (r=.13; p=.002)

• Personal pronouns: – Density of first person plural and third person singular pronouns

positively correlates with charisma (r=.16, p=0; r=.16, p=0)

– Third person plural pronoun density correlates negatively with charisma (r=-.19,p=0)

• Content: Ratio of adjectives/all words negatively correlates with charisma (r=-.12,p=.008)

• Complexity: Higher mean syllables/word positively correlates with charisma (p=.034)

• Disfluency: greater % negatively correlates with charisma (r=-.18, p=0)

• Repetition: Proportion of repeated words positively correlates with charisma (r=.12, p=.004)

Results: Acoustic-Prosodic Correlates of Charisma

• Pitch: – Higher F0 (mean, min, mean HiF0, over male speakers)

positively correlates with charisma (r=.24,p=0;r=.14 p=0;r=.20,p=0)

• Loudness: Mean rms and sdev of mean rms positively correlates with charisma (r=.21,p=0;r=.21,p=0)

• Speaking Rate: – Faster overall rate (voice/unvoiced frames) positively

correlates with charisma (r=.16,p=0)

• Duration: Longer duration correlates positively with charisma (r=.09,p=.037)

• Length of pause: sdev negatively correlates with charisma (r=-.09,p=.004)

Results: Intonational Correlates of Charisma (Hand-Annotated Features)

• Pitch Accent Type:– Positive correlation with !H* and L+H* accents

(r=.09,p=0;r=.09,p=.034)

– Negative correlation with L*, H* and L*+H accents (r=-.13,p=.002;r=-.11,p=.014;r=-.08,p=.052)

• Phrasal Types– Negative correlation with !H-L% and !H- endings

(r=-.11,p=.015;r=-.10,p=.026)

Summary for American English

• In Standard American English, charismatic speakers tend to be those also highly rated for enthusiasm, charm, persuasiveness, passionateness and convincingness – they are not thought to be boring

• Charismatic utterances tend to be longer than others, to contain a lower ratio of adjectives to all words, a higher density of first person plural and third person singular pronouns and fewer third person plurals, fewer disfluencies, a larger percentage of repeated words, and more complex words than non-charismatic utterances

• Charismatic utterances are higher in pitch (mean, min) with more regularity in pause length, louder with more variation in intensity, faster, and with more !H* and L+H* accents and fewer L*, H*, and L*+H accents and fewer !H- and !H-L% phrasal endings

Replication of Perception Study from Text Alone

• Lower statement agreement, much less on charismatic statement, different speakers most/least charismatic

• `Agreement with speaker’, genre and topic had stronger correlations

• Lexico-syntactic features show weaker correlations– 1st person pronoun density negatively correlated and

complexity not at all– Similar to speech experiment for duration,

function/content, disfluencies, repeated words

Hypothesis: Charisma is a Culture-Dependent Phenomenon

• People of different languages and cultures perceive charisma differently

• In particular, they perceive charisma in speech differently– Do Arabic listeners respond to American politicians the

same way Americans do?

– Do Americans hear Swedish professors the same way Swedish students do?

Charismatic Speech in Palestinian Arabic

• Are these tokens charismatic?:

• Are these?:

Palestinian Arabic Perception Study

• Same paradigm as for SAE• Materials:

– 44 speech tokens from 22 male native-Palestinian Arabic speakers taken from Al-Jazeera TV talk shows

– Two speech segments extracted for each speaker from the same topic (one we thought charismatic and one not)

• Web form with statements to be rated translated into Arabic

• Subjects: 12 native speakers of Palestinian Arabic

How Does Charisma Differ in Arabic?

• Subjects agree on judgments a bit more (κ=.225) than for English (κ=.207) but still low– Agree most on clarity of msg, enthusiasm, charisma,

intensity – all differing from Americans

– Agree least on desperation (as Amer), friendliness, ordinariness, spontaneity of speaker

– Charisma statement correlates (positively) most strongly with speaker toughness, powerfulness, persuasiveness, charm, and enthusiasm and negatively with boringness

• Role of speaker identity important in judgments of charisma in Arabic as in English– Most charismatic speakers: Ibrahim Hamami (4.75),

Azmi Bishara (4.42), Mustafa Barghouti (4.33)

– Least: Shafiq Al-Hoot (3.10), Mohammed Al-Tamini (3.42), Azzam Al-Ahmad (3.33)

– Raters claimed to recognize only .55 (of 22) speakers on average, perhaps because the speakers were less well known than the Americans

• Topic important in charisma ratings (r=0,p=.043)Israeli separation wall > assassination of Hamas leader >

debates among Palestinian groups > the Palestinian Authority and calls for reform > the Intifada and resistance

Lexical Cues to Charisma

• Length in words positively correlates with charisma, as for Americans

• Disfluency rate negatively correlates, as for Americans

• Repeated words positively correlates with charisma, as for Americans

• Presence of Arabic ‘dialect markers’ (words, pronunciations) negatively correlates with charisma

• Density of third person plural pronouns positively correlates w/ charisma – differing from Americans

Acoustic/Prosodic Cues to Charisma

• Duration positively correlated with charisma, as for Americans

• Speaking rate approaches negative correlation – opposite from American – But rate of the fastest intonational phrase in the token

positively correlated for both languages– Sdev of rate across intonational phrases positively

correlated for charisma in Arabic

• Pauses– #pauses/words ratio positively correlated with charisma

but not for Americans

– Sdev of length of pause positively correlated in Arabic but negatively for Americans

• Pitch: – Mean pitch positively correlates (as for Americans) but

also F0 max and sdev

– Min pitch negatively correlates (opposite from Americans)

• Intensity: Sdev positively correlates w/ charisma

How Are Perceptions of Charisma Similar Across Cultures?

• Level of subject agreement on statements• Role of speaker ID, topic in charisma judgments• Positive correlations with charisma

– Mean pitch and range

– Duration, repeated words

– Speaking rate of fastest IP

• Negative correlations with charisma– Disfluencies

How Do Charisma Judgments Differ Across Cultures?

• Statements most and least agreed upon• For Arabic vs. English:

– Positive correlations with charisma

• Sdev of speaking rate, pause/word ratio, sdev of pause length, F0 max and sdev, sdev intensity

– Negative correlations with charisma

• Dialect, density of third person plural pronouns

• Speaking rate, min F0

Future Work

• Machine learning experiments -- automatic detection of charisma

• Cross-cultural perception experiments: American raters/Arabic speech, Palestinian raters/English speech, Swedish raters/English speech– Do native and non-native raters differ on mean scores

per token? (Yes, for Eng/Swe rating Eng and Eng/Pal rating Arabic)

– Do mean scores correlate per token? (Yes, for all)

• Amer and Swe rating English: – paired t-test betw means per token: p-value = 0.03064– cor between means of rater-normalized ratings: r = 0.60, p-value

= 1.170e-05

• Amer and Pal rating English: – paired t-test betw means: p-value = 0.1048– cor between means of rater-normalized ratings: r = 0.47, p-value =

0.0009849

• Amer and Pal rating Arabic: – paired t-test betw means: p-value = 0.00164– cor between means of rater-normalized ratings: r = 0.72, p-value =

3.049e-08

• Swe and Pal rating English: – paired t-test betw means: p-value = 0.8479 (not normalized) – cor between means of rater-normalized ratings: (rater

normalization) r = 0.55, p-value = 9.467e-05

Thank you!

Arabic Prosodic Phenomena MSA vs. Dialect

• A word is considered dialectal if:– It does not exist in the standard Arabic lexicon

– It does not satisfy the MSA morphotactic constraints

– Phonetically different (e.g., ya?kul vs. ywkil)

• In corpus of tokens– 8% of the words are dialect.

– 80% of the dialect words are accented.

Arabic Prosody: Accentuation

• 70% of words are accented• 60% of the de-accented words are function words

or disfluent items– Based on automatic POS analysis (MADA) – 12% of content words are deaccented

• Distribution of accent types:– H* or !H* pitch accent, 73%– L+H* or L+!H*, 20%– L*, 5%– H+!H*, 2%

Arabic Prosody: Phrasing

• Mean of 1.6 intermediate phrases per intonational phrase

• Intermediate phrases contain 2.4 words on average• Distribution of phrase accent/boundary tone

combinations– L-L% 59%

– H-L% 26%

– L-H% 8%

– H-L% 6%

– H-H% 1%

Arabic Prosody – most common contours

H* L- 21.9

H* H- 13.4

L+H* L- 9.7

H* H* L- 7.6

H* !H* L- 4.1

L* L- 4.1

L+H* !H* L- 3

H* H* H- 3

H* !H* !H* L- 2.3

L+H* H- 2.1

Arabic Prosody – Disfluency

• In addition to standard disfluency:– Hesitations– filled pauses– self-repairs

• In Arabic, speakers could produce a sequence of all of the above. (see praat: file: 1036 and 2016)

• Disfluency may disconnect prepositions and conjunctions from the content word:– تأتي ... ... ... <ولتأتي = يعني لـ و – w- l- uh- yEny uh- t?ty instead of wlt?ty