A study by Durgin and colleagues (2009) finds that the burden of wearing a heavy backpack is lessened when a social purpose is given in form of social demands.
In other words, we perceive the burden as less burdensome, when a social purpose is given. In this way, a purpose contributes to a judgmental bias of the burden.
In 1999, a study reported that hills appeared steeper when participants wore heavy backpacks. A following study in 2003 reported that heavy backpacks also make distances seem longer. But they did not examine why it is so.
Therefore, Durgin and co-workers (2009) decided to find out why some participants perceive their backpacks as heavier, the slopes as steeper, and the distances as longer and vice versa.
It seems that it is when participants attribute their efforts to some kind of purpose (demand), they make a judgmental bias. The study examined how wearing a heavy backpack affects one’s estimates of slope steepness. Participants were put into three experimental conditions:
- A no-weight condition (non purposeful)
- A standard backpack condition where no explanation was given for the backpack (non purposeful)
- An electrode backpack condition where participants were told that their ankle muscles were monitored and that their backpacks were filled with equipment (purposeful)
Results of the experiment:
- Those in the no-weight condition made the lowest estimates of slope steepness
- Those wearing a backpack, where no explanation was given, made the highest estimates of slopes
- Those in the electrode condition made estimates that were almost similar to those who did not wear a backpack at all
- Those wearing a backpack, where no explanation was given, and those who simultaneously found the experimental purpose transparent, they did the highest estimates of all groups
- Those in the electrode condition also memorized the backpacks to be less heavier than group number two
The results speak for themselves.