We keep a jug of filtered drinking water in our fridge. The water from the tap is perfectly palatable but chilled water is that bit nicer so the jug is popular.
It is a matter of seconds to fill the jug but it takes several minutes to trickle through the filter and a lot longer to cool down to a nice level of chilliness. It is therefore very frustrating to reach for the jug and find it empty and I take care to top it up every time I use it. Unfortunately other members of my family do not seem to be as considerate and on many occasions I have gone to the fridge only to be disappointed by a nearly empty jug.
My usual response in circumstances like this is to express my dissatisfaction loudly in what my kids term a "Father Rant". This makes me feel better for a little while but long experience has convinced me that such rants are incapable of producing any lasting change of behaviour. On this occasion therefore I decided to be a little more scientific.
Analysing the problem it soon became clear to me that I was probably the only person who ever filled the jug. Others who used the jug after me found it contained enough water for their needs and used it without replenishment. Because they did not need to fill the jug to meet their own needs they did not think to fill the jug afterwards. When I next came to look for the jug it was invariably almost empty.
My first thought was to stop filling the jug after I use it. My thinking was that I I stopped filling then there wouldn't be enough water for others and eventually it might dawn on them that they have to start filing it themselves. In the interest of science however I decided to take an even bolder approach in order to test the hypothesis in the extreme case. I started emptying the jug completely every time I used it. This required a certain amount of subterfuge but I managed to pull it off for a couple of days.
The results were immediate and conclusive. Every time I went to the fridge I found a full jug of water despite my emptying it completely every time I used it. Clearly the empty jug was providing the signal to others to start filling as anticipated.
I was initially enthused by my experiment. Finally I had discovered a method to change other people's behaviour through the application of scientific principles. How many more familial annoyances might I be able to deal with in a scientific manner: The lights that are left on unnecessarily? The dishes that are not cleared off the table? The toys that seem to accumulate in inappropriate locations?
I was smugly contemplating such future scientific triumphs after having just replaced a carefully emptied jug into the fridge when I noticed my my youngest daughter go to the fridge open it and reach for the jug.
The look of disappointment on her face when she saw it was empty broke my heart and dragged me down to earth with a crash.
The scientific experiments are over. If it is my lot in life to be the filler of water jugs so be it.