Manual dishwashing process - a pre-assigned behaviour?

Global studies have observed many techniques of manual dishwashing causing different levels of performance and using quite different amounts of water, energy, time and detergent. It is not known, however, if these techniques are pre-assigned to a person and persist when dishes are washed under different conditions, or are adapted to the specific type of dish-cleaning process. Here we explored this question in a study with 40 test subjects selected equally from Germany and East European countries by asking them to wash two place settings of dishes with different amounts of soil three times. The results showed that the test subjects did not adapt their washing-up behaviour to the amount of soil. In general, no significant differences were found in the water, energy and detergent consumption for all test subjects. Only the time used by the German test subjects to wash the fully soiled dishes was significantly longer compared with the dishes with only a quarter the quantity of soil, and no significant difference was observed for all other parts. The only significant difference found between the level of soiling of the dishes was the cleaning result achieved: The less soiled the dishes were, the better the final cleaning result was, and this related to all test subjects. This lends support to the proposition that the consumers did not adapt their washing-up behaviour to the specific circumstances of the dishwashing job to be done but retained some pre-assigned behaviour.