A recent survey shows a significant proportion of people believing in astrology and Tarot (BBC News, 12 April 2009). The number of believers is slightly down from the 1990s, but still much higher than in the 1950s.
One reason why these beliefs are popular is because they appear to work: practitioners of fortune-telling sometimes produce excellent insights. However, this can be explained as follows.
We start with the theory that the human brain is divided into leftbrain and rightbrain.
We then observe that fortune-telling typically involves a complicated procedure, and sometimes complicated calculations. This applies to a range of practices, including astrology, iChing and Tarot. Sceptics typically dismiss this as pseudo-scientific mumbo-jumbo.
However, all of these procedures and calculations have the effect (and so perhaps the purpose) of occupying the leftbrain, while the rightbrain quietly produces some interesting and relevant insight. In other words, the more complicated the procedure the more effective it is.
See my post on Confirmation Bias