Bias against, discrimination towards, or bullying of individuals and groups based on their age. Ageism affects everyone. Children as young as four years old become aware of their culture’s age stereotypes. From that age onwards, they internalize and use these stereotypes to guide their feelings and behaviour towards people of different ages. They also draw on culture’s age stereotypes to perceive and understand themselves, which can result in self-directed ageism at any age. Ageism intersects and exacerbates other forms of disadvantage, including those related to sex, race, and disability.