Why do the slaves who are also the illegitimate children of the slaveholder suffer more than other slaves?

Kids of slave masters and slaves were often shunned by both races, they were caught between two cultures both hostile to them. Slave masters did not want to acknowledge their sinful acts and these children were a constant reminder. Slave children unlucky enough to have their white masters as fathers were tortured and persecuted at every turn. They often paid the price for the jealousy of their master's white wives.