History also supports this. In the great depression of 1929, Gold was the best performing asset. People had even dumped the currencies and converted to Gold with the fear of even central banks being fail. At that point in time, Gold was the standard on which each currency value was measured. Dollar was fully convertible to Gold and so were many other currencies.
Similar trends can be seen today with the upward movements in Gold prices, while the other asset classes are deteriorating in value. Analysts have confirmed, that the large investors and many hedge funds are dumping stocks and moving to the yellow metal on the fear of a global recession.