The stereotype of the grumpy elderly person is not backed by science, according to Eva-Marie Kessler, a gerontopsychologist (a specialist in the psychology of ageing) at the Medical School Berlin. She argues that most older people experience what researchers call a "positivity effect" — as they perceive their remaining time as limited, they tend to focus on what is meaningful and avoid stress, making them generally more content rather than more bitter. Kessler also pushes back on the term "age-related depression," noting it wrongly implies that old age itself causes depression, and stresses that feelings of bitterness at any age are more often linked to experiences of injustice or betrayal than to ageing itself.