Humans are programmed, or designed, to need relationships.
Harry Harlow, a professor of psychology at the University of Wisconsin at Madison, produced a series of influential studies involving baby rhesus monkeys.
This showed that while they would grow fit and strong without contact with others, they would also show signs of mental illness if kept in isolation. His findings have also shown themselves true of humans.
In practice, while we need and appreciate relationships, not all of them are positive. This section looks at various types of relationships and aims to help us make the most of them.