Independent system attributes drive unnitended disparate impact

From American Heroes: Profiles of Men and Women Who Shaped Early America by Edmund S. Morgan. Page 117.

The events leading up to the Salem episode are thought to have begun with the case of the Goodwin children in Boston. The four Goodwin children, the eldest of whom was thirteen, began in the fall of 1688 to show signs of being bewitched. Led by the eldest girl, they fell into fits and convulsions in which they would complain of agonizing pains, now here now there. Their tongues would hang out, and they would simulate blindness and deafness and dumbness for periods of a couple of hours. In between seizures they would behave normally. The oldest Goodwin girl accused an old Irish woman with whom she had had a quarrel of bewitching them. And the woman was accordingly brought to trial.

This pattern, incidentally, was common in witchcraft cases in England. The accused witch was usually someone with whom the accuser had had a quarrel, a quarrel in which the accuser was conscious of having in some way injured the accused. For example, a man might have turned away an old woman who came to his door begging a cup of milk. Later his cow would die, and he would accuse the old woman of having bewitched it in revenge for his failure to give her the milk. The accused person was usually poor and old, and since more women were poor and old than men, witches, at least in England, were most likely to be old and to be women.