Savage and Torgler point out that after a death has occurred, commercial expeditions go on to record a successful climb in 80.6 percent of cases, but only 37.8 percent for the non-commercial expeditions.
"The Sherpa appear to embody and hold to the pre-commercial values of behavior, which has been weakened in the modern climbers, and is faintly visible in the non-commercial expeditions," Savage concluded.
Unlike commercial expeditions, a death in a non-commercial venture has a highly significant negative impact on the probability of success, indicating a willingness to stop or abandon expeditions.
"Given the multitude of anecdotal reports, books and newspaper stories about the behavior of modern climbers, these results did not come as a surprise to me," Savage told Discovery News.
"However, I was not expecting to find that the non-commercial climbers had started to weaken as well," he said. "The Sherpa may be responsible for the remaining prosocial behavior," he said.
Richard Salisbury, the co-creator of the Himalayan Database used in the study, told Discovery News he was not surprised by the findings, although he believes they need to be confirmed by further research and methods.