The research showed that volunteers who gazed at their reflections for up to ten minutes at a time gradually became more and more anxious and depressed about their looks - even if they were perfectly happy with them to start with.

Scientists admitted that the findings were surprising because they had only expected prolonged mirror gazing to adversely affect volunteers in the experiment who had already been diagnosed with the condition Body Dysmorphic Disorder - where sufferers permanently worry about their looks or shape.