The image of the 'blue and black or white and gold dress' that went viral this year split friends and families over the colour of its stripes. Now scientists have found it may look different to early risers and night owls.
Bevil Conway, a researcher at Wellesley College and MIT, asked 1400 people, 300 of whom had never seen the picture before, to describe the dress. Overall, 57% said it had blue and black stripes, 30% saw white and gold stripes, and another 10% saw blue and brown. About 10% could switch between either colour combination.
But among the responses, Conway saw another pattern. Women and older people were more likely to see the dress as white and gold, while the same group are more likely to be larks, being awake in sunlight hours, rather than owls, who were awake more at night time.
He speculates that people who stay up later have more experience of artificial lighting which has more reddish light in it. Their brains may then be accustomed to correcting from reddish illumination. Take these colours out of the dress image, and it appears blue and black.
Conversely, people who are awake in daylight hours are exposed to more natural light, which contains more blueish light than artificial light. If the brain assumed the dress was illuminated by more natural sunlight, and corrected for blueish illumination, the colours appear more white and gold.
Whether you are an early riser or night owl, find helpful sleep tips in our Sleep toolkit