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Earthquake Perceptions

Damage from earthquakes is not solely due to the physical force involved, but can also be a result of community perceptions of earthquakes and the effects on preparedness, according to a study carried out by Victoria University researchers.

People often fail to distinguish the damage caused by earthquakes from the uncontrollable force of earthquakes themselves. Although damage factors inherent in an earthquake cannot be controlled, factors in the design and siting of buildings and other structures can be.

"This fatalistic view may be accentuated by news reports and well-intentioned civil defence warnings that solely stress the damage caused by earthquakes," says John McClure of Victoria's Department of Psychology.

Perceiving earthquake damage as uncontrollable implies a type of attribution for that damage, and may affect preparedness for earthquakes. If people attribute earthquake damage to uncontrollable causes, they are less likely to prepare for such events.

In contrast, if they attribute damage to controllable causes, such as building design, they are then aware that preventative action may make a difference. This attribution may not always be sufficient to make people (or organisations) take preparatory action, but it is a necessary condition for voluntarily doing so.

Theories of attribution processes in psychology suggest that when outcomes are distinctive -- that is, exceptional -- people invoke the causal factor that varies along with the outcome. So when earthquake damage to a building is distinctive, such as when one building in a street collapses while others are undamaged, observers tend to attribute the damage to some aspect of the building, such as its design. When earthquake damage is not distinctive, as when every building in a street collapses, observers are likely to attribute the damage to the magnitude of the earthquake.

Attributions also reflect "consensus" information --  whether other earthquakes produce the same effect. Consensus is high when other earthquakes have damaged buildings of the same type as the target case. These principles apply to other structures such as bridges or elevated freeways.

McClure and his team tested these propositions, by obtaining people's judgements about scenarios that varied in distinctiveness and consensus.

"We examined ratings of how preventable the damage was and which explanation was better -- building design, earthquake magnitude, or both. The predictions were supported, in that damage that was highly distinctive or was high in consensus was seen as more preventable and was attributed more to building design than damage that was undistinctive and low in consensus."

This finding has clear implications for news agencies and civic agencies, says McClure.

"These sources of public information could reduce fatalism about earthquakes if they stressed that damage from even major earthquakes in countries with adequate building regulations is often distinctive and affects structures that have been damaged in other earthquakes. This pattern leads people to see the damage as preventable and attributable to the design of the relevant structures."