The researchers
focused their study on traffic enforcement agents in the city because of
the stressful nature of traveling around the city issuing
parking
tickets and other vehicular violations. “Motorists often insult, threaten
or curse at the agents, and in previous studies agents have reported an average
of three negative interactions with motorists per day,” say study authors
Elizabeth Brondolo, Ph.D., and William Karlin, Ph.D., of the Department of
Psychology at St. Johns University in Jamaica, N.Y.
But high levels of interpersonal stress at work are not
unique to traffic agents. “Other law enforcement groups, customer service representatives
and others are exposed to high rates of interpersonal stress at work and may
be responsive to workplace social support,” Brondolo adds.
Previous studies have found emotional support from a network of family and
friends is protective against cardiovascular disease, but the exact mechanism
remains poorly understood. One line of thinking, called the main-effect model,
suggests that social isolation has a negative effect on heart health in both
stressful and non-stressful times. In contrast, the buffer-effect model suggests
that social support protects against blood pressure and heart rate increases
only under high-stress conditions.
Brondolo and colleagues tested both of these models with
the help of 70 male and female New York City traffic enforcement agents,
aged 22 to 58 years.
More
than half of the agents were African American, and the rest were Latino,
Asian, white, Native American or of mixed race. An unobtrusive unit strapped
to the
participants’ chests monitored their blood pressure and heart rate
throughout the workday. The participants also completed journal entries on
their workday
whereabouts and activities, and they completed a questionnaire measuring
their perceived emotional support from coworkers, immediate supervisors and
unit
supervisors.
Brondolo and colleagues found that workplace social support
was associated with lower blood pressure during acute periods of stress,
and generally lower
blood pressure levels throughout the workday. In general,
the researchers found more support for the buffer-effect model than for the
main-effect model; that is, the strongest
heart-protective effects of social support emerged in high-stress rather
than low-stress conditions. The most stressful work activities for the
traffic agents were issuing summonses and communicating with motorists.
“Our results are consistent with a body of laboratory research that
suggests that the presence of a socially supportive person reduces cardiovascular
reactivity in socially threatening situations,” says Brondolo. The
study results are published in the current issue of Psychosomatic Medicine.
The researchers also noted males and females had different preferred sources
of social support. Lower blood pressure among females tended to have a link
with immediate supervisor support, while males tended to benefit from co-worker
support. These findings are consistent with previous research.
“Men may benefit more than women from coworker support because close
social relationships may sometimes be a source of stress or demand for women,” Brondolo
says. “Both men and women are more likely to seek social support from
women and playing the role of caregiver or support provider can be demanding
and stressful.”
Different sources of workplace
social support were also found to have different effects on heart rate and
blood pressure measurements.
For example, while
support from an immediate supervisor exerted a positive effect on the participants’ workday
blood pressure and heart rate measurements, support from a unit supervisor
support had no significant effect.
“Agents have relatively little contact with their unit supervisors,
whereas they frequently interact with their immediate supervisors and coworkers,” Brondolo
notes.
“Overall the relations of workplace social support
to workday blood pressure measurements may be complex in that they may
depend on the source
of workplace support, the gender of the participant, the level of stress
in a given situation, and the measure of cardiovascular response,” Brondolo
concludes. “Future research on work-place social support should pay
particular attention to these potential moderating factors.”
This work was supported by a grant from the National Institute of Mental Health.
