All people need food, shelter, company, air and water. The ways people fulfill these needs depends on their cultural background. Each society has its own sets of behavioral rules and artefacts to organise a framework of consensus reality, or cultural habits.
The furniture used for seating poses a good example for manifested cultural habits. Instead of just supporting our sit bones, we got used to slump onto the back of any seat we plummet in (okay, not everyone does sit down like that, but have a look around you when people sit down). Instead of using the support of gravity, we collapse habitually into a distorted position.
Especially education systems shape movement patterns a lot, often without a proper understanding of the structural functionality of human bodies or plain ignorance thereof. Sitting still in class room, interpreting tension as desirable 'effort', and physical education focusing on competition, a typical situation in western education systems, create a fertile ground for health problems related to habitual misuse of the body.