UGLY LEGS

This quote is to be found on the wall in the gents toilet aboard one of Stena Line's ferries plying the route from Denmark to Sweden.  

I have no idea why the quotation was there, and even less of an idea why it should be accompanied by pictures of eggs and apples.  However, there are some important scientific questions it raises:

How would you investigate this claim?  
Is it really a law?  
What would a graph of the results of your investigation look like?

Gothenburg, Sweden, 08/2004