A slew of studies have recently documented the ways in which poverty can be as toxic to a developing brain as drugs or alcohol. The conditions associated with poverty - "overcrowding, noise, substandard housing, separation from parents, exposure to violence, family turmoil" and others - cause the brain to release cortisol, a stress hormone. Long term exposure to cortisol is toxic for the brain. This effect can also be transmitted inter-generationally: pregnant women can transmit cortisol to the developing fetus.