Mountain Safety Note

- Group Size -

Date: Thu, 29 Jan 1998
Subject: Safety - Group Size

Group size

Large groups decrease safety in at least two ways - increased exposure to objective hazard and decreased ability to make sound decisions.

One of the factors human decisions are affected by is sometimes called the "herding instinct" (also known as the "sheep" or "lemming" mentality) . More people often equates in our minds to more security, whether or not reality supports this perception. Suddenly something that we might be nervous about in a smaller group seems safer. This is compounded by the fact that it is much more difficult to voice concerns in a larger group. Nobody wants to be the one to put a damper on things. It is easy to justify not voicing concerns in a large group since out of all these people somebody else always seems to be more experienced, and if they don't question anything then there must not be anything wrong.

A second problem with a large group is that there will be more people above other people to knock rocks down on them, start snow moving down on them, or fall onto them. All of these are common sources of mountain accidents. Early this past summer there was a University of Alaska accident in which twelve people were climbing together. One fell, which brought all twelve of them down a 1000 foot slope with disastrous consequences. (In addition to group size there seem to have been problems with leadership, roping up, and perhaps route selection - probably all related. However, I am not currently in a position to comment in more detail on these aspects.)

So how large a group is ok? That depends on what the activity is and what the skills of the group as whole and the leaders in the group are. A limit is imposed in many cases by the agency managing the land - USFS wilderness rules typically limit groups to 12. However, this is still too large for mountaineering. I limit most of my classes to six and usually limit climbs to less. You can take a large group and make two or more smaller groups out of it - just make sure that one group does not create a hazard to the other(s) and that there is sufficient gear and enough leaders.

Mountain Safety Notes