Four Perspectives on . . .
13
According to U.S. government statistics, influenza and influenza-related pneumonia
together comprise the sixth most common cause of death in the United States
(http://www.cdc.gov). Furthermore, influenza can exacerbate existing medical conditions (i.e.,
asthma, heart disease, emphysema, AIDS, diabetes) and lead to additional medical complications
(http://www.cdc.gov). Thus, influenza is a public health issue of considerable consequence.
To construct the stimuli, information from a variety of professional health resources was
collected. Arguments advocating vaccination were supported by evidence from expert sources
(e.g., CDC, World Health Organization) and presented in both a narrative and a statistical form
in both messages. Table 1 provides a summary. Two versions of the message, low threat and
high threat, were created. The high threat version contained more vivid language and a more
personal narrative than did the low threat version.
1
Measures
BIS/BAS Scales. Tonic levels of BIS and BAS activation were assessed using Carver and
White’s (1994) questionnaire. Participants responded to each of the 20 items on a 4-point scale
where 1 = Strongly Disagree, 2 = Disagree, 3 = Agree, and 4 = Strongly Agree. Sample items
from the BIS scale include “If I think something unpleasant is going to happen I usually get
pretty worked up” and “I worry about making mistakes.” Sample items from the BAS scale
include “When I get something I want, I feel excited and energized” and “When I want
something I usually go all-out to get it.” Evidence of the validity of the scales can be found in
studies that demonstrate covariation between the two scales and EEG activity (Harmon-Jones &
Allen, 1997; Sutton & Davidson, 1997).
Convention