Basic living conditions in Scotland were poor - black houses, no windows or chimneys, diseases (typhus, cholera) spread quickly in poor living conditions. People migrated to the cities or abroad to escape.
Countries overseas offered a pleasant climate which contrasted with the wet weather, hardships and poor living of the Highlands.
Family and relations abroad wrote letters home telling of better wages, climate, living standards, etc.
The lack of social life in rural areas and isolation in the Highlands led people to migrate to the cities which offered football, theatre, music halls and other social facilities.
Education Act 1872: All children aged 5-13 received free education. Easier to access in the Lowlands, so many were encouraged to move south for education.