This document summarizes a study that examined how the race of a weight loss vlogger affects viewers' perceived credibility, self-efficacy, and intentions to lose weight. The study found that viewers perceived racially congruent vloggers as more credible sources and reported greater intentions to exercise, compared to racially incongruent vloggers. However, this effect was stronger for Asian American viewers with low ethnic identity and White American viewers with high ethnic identity. The study provides insights into how spokesperson race functions as a cue of expertise and impacts message processing in online health contexts.

1. Effects of vlogger race on perceived
credibility, self-efficacy and behavioral
intentions towards weight loss
Mengmeng Tang
May 2016

2. Study Inspiration
 Popularity of Weight Loss in the US
 57% of American women want to lose weight (Brown, 2013).
 Social Media as a supportive community
 5,920,000 results of “how to lose weight” in YouTube search
 555,000 results of “how to lose weight, vlog” in YouTube search
 Trends in Weight Loss Vlogs
 Most weight loss blogs and vlogs are owned by White American women (Diet-
to-go, 2013; Healthline, 2015; Shape Magazine, 2015)
 RQ: How does vlogger race affect audience’s attitudes, self-efficacy and
behavioral intentions when attempting to lose weight?

3. Prior Literature
The Elaboration Likelihood Model
 Elaboration Likelihood (Petty, Barden, & Wheeler, 2009; Petty
& Cacioppo, 1986).
 The central route to persuasion
 The recipient has both the motivation and the ability to
think carefully
 The peripheral route to persuasion
 The recipient uses simple cues and mental shortcuts to
process information

4. Prior literature
Spokesperson effects
 Characteristics of the spokesperson can affect how people process a
message, either via central or peripheral route.
 Expertise
 Expert sources are perceived as more credible (Ohanian, 1991), and more
effective in changing attitudes and behaviors (Gotlieb & Sarel, 1991;
Heesacker, Petty, & Cacioppo, 1983; Homer & Kahle, 1990).
 Race
 Racially congruent spokespersons increase elaboration (Appiah, 2001;
Whittler, 1991; Whittler & DiMeo, 1991).
 Past research focuses on Black vs. White, advertising context
 Moderated by audience ethnic identity (Green, 1991; Whittler, 1991).

5. Prior literature
Behavior Change
 Theory of Planned Behavior
 Behavior is an outcome of attitude, subjective norm and perceived
behavioral control (Ajzen, 2002).
 Self-Efficacy and Social Cognitive Theory
 Self-efficacy is “the beliefs in one’s capabilities to organize and execute the courses
of action required to produce given levels of attainments.” (Bandura, 1998, p. 624)
 Self-efficacy is obtained from past performance, verbal persuasion, emotional cues,
and vicarious experience(Bandura, 1997).
 The unique issues with weight control
 The beliefs in one’s abilities to control weight through weight-control strategies
 People with high self-efficacy in weight control are more likely to successfully lose
weight (Choo & Kang, 2014; Dennis & Goldberg, 1996; Kitsantas, 2000)

6. Hypotheses
 H1: Participants who watch a racially congruent (RC)
vlogger will report greater (message and source)
credibility, self-efficacy, and behavioral intentions,
compared to those who watch a racially incongruent
(RI) vlogger.
 H1a: Participant race will moderate the effect of race
congruency. This effect will be stronger for Asian American
participants.
 H1b: Participant race and ethnic identity will moderate the
effect of race congruency. This effect will be stronger for
Asian American participants with high ethnic identity and
White American participants with low ethnic identity.
 H1c: Vlogger expertise will moderate the effect of race
congruency. This effect will be stronger for participants who
watch a health vlogger.

7. Hypotheses
 H2: Message credibility will mediate the effect of
race congruency on behavioral intentions.
 H2a: Message credibility will mediate the effect of the 2-
way interaction (race congruency, participant race)on
behavioral intentions.
 H2b: Message credibility will mediate the effect of the 3-
way interaction (race congruency, participant race and
ethnic identity) on behavioral intentions.
 H2c: Message credibility will mediate the effect of the 2-
way interaction (race congruency, vlogger expertise) on
behavioral intentions.

8. Hypotheses
 H3: Self-efficacy will mediate the effect of race
congruency on behavioral intentions.
 H3a: Self-efficacy will mediate the effect of the 2-way
interaction (race congruency, participant race)on behavioral
intentions.
 H3b: Self-efficacy will mediate the effect of the 3-way
interaction (race congruency, participant race and ethnic
identity) on behavioral intentions.
 H3c: Self-efficacy will mediate the effect of the 2-way
interaction (race congruency, vlogger expertise) on
behavioral intentions.

9. Methodology
 2X2 cross-sectional, between-subject, posttest-only
experimental design
 Stimuli
 A pretest guided the selection of spokespersons
 Video production
Racially
congruent (RC)
Racially
incongruent (RI)
Health Vlogger
Fashion Vlogger

11. Methodology
 2X2 cross-sectional, between-subject, posttest-only
experimental design
 Stimuli
 A pretest guided the selection of spokespersons
 Video production
 Participants and procedure (N = 98)
 Participants were recruited online via Amazon Mturk
 Completed demographic information
 Viewed Video
 Completed Measures

12. Methodology
 Measures and scale reliability
Variable Cronbach’s Alpha
Attitude towards exercising .65
Attitude towards dieting .56
Attitude towards drinking water .50
Behavioral intention towards exercising .78
Behavioral intention towards dieting .92
Behavioral intention towards drinking water Single item
Self-efficacy towards exercising .84
Self-efficacy towards dieting .86
Self-efficacy towards drinking water .64
Source credibility .91
Message credibility .88
Ethnic identity .83

13. Results &
Discussion

14. Preliminary Results
 Manipulation check
 Vlogger face confirmation
 Vlogger expertise confirmation
 Group difference in variables (see Table 4.2)
 A>W Behavioral intention towards dieting (p = .071)
 A>W Ethnic identity (p < .001)
 Correlation between variables (see Table 4.3)
 Behavioral intentions towards exercising and dieting (r = .25, p = .012)
 Self-efficacy towards exercising and dieting (r = .61, p < .001)
 Source credibility and message credibility (r = .57, p < .001)
 Main effect of vlogger expertise on message credibility
 Participants who watched a health vlogger reported marginally significant
greater message credibility compared to those who watched a fashion
vlogger (p = .083).

15. H1: RC will result in greater
credibility, self-efficacy and BI
 H1: Participants who watched a racially congruent vlogger
reported marginally significant greater source credibility
compared to those who watched a racially incongruent
vlogger, (p = .062).
 Race congruency did not affect message credibility, self-
efficacy and behavioral intentions.
 H1a: The interaction of race congruency and participant
race predicted…
 Message credibility (p = .049), behavioral intention towards
exercising (p = .09), and dieting (p = .051).
 Asian American participants reported significantly greater
message credibility and behavioral intentions after watching a
racially congruent vlogger.
 White American participants reported significantly greater
behavioral intentions after watching a racially incongruent
vlogger.

16. H1: RC will result in greater
credibility, self-efficacy and BI
 H1b: The interaction of race congruency, participant
race and ethnic identity predicted…
 self-efficacy towards exercising (p = .02), and dieting (p =
.03).
 The effects of H1a were only present for participant with low
ethnic identity.
 H1c: The interaction of race congruency and vlogger
expertise marginally predicted behavioral intention
towards exercising (p = .085).
 Participants in racially congruent group reported marginally
significant greater behavioral intention towards exercising
after watching a fashion vlogger compared to a health
vlogger.

17. H2: Message credibility will
mediate RC on BI
 H2a: Message credibility mediated the effect of the 2-
way interaction (race congruency, participant race) on
behavioral intentions.
 H2, H2b, H2c could not be tested because race congruency,
the 3-way interaction (race congruency, participant race,
participant ethnic identity), and the 2-way interaction (race
congruency, vlogger expertise) failed to predict message
credibility in the first place.

18. H3: Self-efficacy will mediate
RC on BI
 H3, H3a, H3c could not be tested because race
congruency, the 2-way interaction (race congruency,
participant race), and the 2-way interaction (race
congruency, vlogger expertise) failed to predict self-
efficacy in the first place.
 H3b could not be tested because the 3-way interaction
(race congruency, participant race, participant ethnic
identity) did not predict behavioral intentions.

19. Discussion
 The findings were in line with past research…
 Race congruency between vlogger and audience resulted
in better evaluations for Asian American participants.
 This effect was stronger for Asian American participants
with low ethnic identity.
 People from minority ethnic groups are more receptive
and attentive to the cue of source race (Arpan, 2002).
 Vlogger race functions as a cue of expertise.

20. Discussion
 The findings were novel…
 Race incongruence between vlogger and audience resulted in
better evaluations for White American participants.
 This effect was stronger for White American participants with low
ethnic identity.
 Why might this be…
 Model minority myth stereotype (Cheryan & Monin, 2005)
 Perceived expertise in health (Min & Jang, 2015)
 People with low ethnic identity are more open to other cultures
and susceptible to stereotypes of other races (Appiah, 2002).

21. Discussion
 The finding was novel…
 The current study identified the underlying mediation
mechanism between spokesperson race and audience’s
behavioral intentions.
 The interaction of race congruency and participant race
first affected message credibility, which then affected
behavioral intentions.
 Source race functioned as a central processing cue.

22. Implications of the current study
 A novel form of inter-racial communications
 Spokesperson effect in the interactive media
environment
 Spokesperson race as expertise