BUFFALO, N.Y. -- When a serious threat of a flu epidemic arises, public health officials advise persons to stay away from crowds and, as importantly, avoid shaking hands.

But a Viewpoint piece in the current issue of Public Health Reports, authored by University at Buffalo public health faculty members, illustrates that, in certain situations, social pressures make such recommendations moot.

The setting in question was the 2009 commencement ceremony for UB's School of Public Health and Health Professions. As pointed out in the Viewpoint article, concern was growing at that time about the seriousness of the then-novel H1N1 virus.

Before presenting the diplomas, Lynn T. Kozlowski, PhD, dean of the school, announced from the stage that, given the potential of spreading the virus, shaking hands when receiving a diploma was optional. A doff of the cap would be a suitable substitute sign of respect.

"The results of the handshaking-optional announcement were striking," says Kozlowski. "All 200 graduates shook hands without apparent hesitation."

It was clear that the brief ceremonial encounter involving a handshake and a few congratulatory words was important to the graduates. "I felt that we were caught up in a moment of great significance and emotional importance that overshadowed the then-existing health concern about the flu," says Kozlowski.

The authors -- UB public health faculty members Marc Kiviniemi, PhD, and Pavani Ram, MD, in addition to Kozlowski -- comment in the article that graduation is an important rite of passage and graduates did not consider passing on the handshake a genuine option.

"The behavior of individuals in social settings is based on a complex web of social and environmental forces that guide individuals toward or away from certain behaviors in certain situations," they write.

"A graduation is a socially significant gathering and a ritually charged ceremony, marking a personally and socially important transition. Handshaking is part of the dramatic scripting of the graduation ceremony, and is expected of those who take part."

Kozlowski says that seeing the first graduate shake hands may have put pressure on the second graduate, and the third graduate, and so on, to do the same.

He notes that when public health officials have serious concerns about disease transmission, they need to issue a mandate, or outright ban, on handshaking or other behaviors, rather than "recommendations."

The authors report that at the same time as the UB graduation in 2009, the Indiana state health commissioner explicitly recommended in a press conference that "Indiana stop shaking hands." As a result, several Indiana universities announced that no handshaking would take place at graduation. Everyone adhered to the ban.

"The take home message," says Kozlowski, "is 'Beware the power of social demands.' Preventing disease transmission by social distancing may be easier said than done.

"We recommend that communications aimed at preventing infectious disease transmission in public gatherings provide guidance that is both socially and behaviorally practical, even though those practical steps may require more extreme measures, such as banning handshaking or canceling events, if preventing disease transmission is to be truly effective."

The University at Buffalo is a premier research-intensive public university, a flagship institution in the State University of New York system and its largest and most comprehensive campus. UB's more than 28,000 students pursue their academic interests through more than 300 undergraduate, graduate and professional degree programs. Founded in 1846, the University at Buffalo is a member of the Association of American Universities.