Whichever culture you go to black cats will always have something to do with luck. The belief seems to be black cats can absorb all the luck around them. Some cultures think this makes them lucky because they will then share that luck, but others think they take away the luck and keep it for themselves. This is why when a black cat walks across your path its unlucky because its taking the luck away from your future where you were headed. Going back around the cat supposedly continuous your path, if you can manage to run around it. However there is also the old belief that black cats were witches and devils in disguise which added to the distrust of black cats.