Bob’s Your Uncle wrote: “It was when the Lowland and English legal systems came to prevail in Scotland that male inheritance became the way property was transferred from one generation to another.”

I understand that King Malcolm III Canmore had most to do with this shift.
He fought a bloody war that devastated Buchan in order to ensure that he would be succeeded by his sons, and in the end six or seven of them actually sat on the throne in succession.
Regards,
Mike