Safety culture has become increasingly popular as a way of explaining why major accidents happen and as a goal that people aim to achieve. Psychologists study culture by distributing and analysing surveys but this approach is essentially ad hoc and self-fulfilling. In order to have a list of dimensions that are relevant to understand a safety culture, it is necessary to have an understanding of both what the organisation says but also what it does. One approach that has proved fruitful distinguishes a sequence of five different cultures, from the pathological to the generative, often called the safety ladder. This paper tells the history of safety culture and explains how the descriptions in the safety ladder were obtained from experienced managers. These descriptions are then used to develop improvement programs after identifying what an organisation aspires to achieve. A later but major change to the scoring methodology resulted in people identifying the gaps between their current and aspired cultures. This allowed correction for overestimation of the current culture and the identification of specific gaps between the current and aspired cultures. More recently, the dimensions have been extended to include process safety culture. The more recent refinement of the safety ladder and its dimensions has clarified the underlying factors that explain the descriptions that are generated.