pecking order vs social order

pecking order

noun
  • The natural hierarchy of social status and dominance occurring in a group of birds. 

  • The usually informal hierarchy of authority or command, often partial or approximate, as determined by the especially natural propensity for domination of different members of a specific group over each other, such as older brothers and sisters over their younger siblings. 

social order

noun
  • A particular system of social structures, institutions, customs, values, and practices which conserve, maintain, and enforce certain societal relations and behavioral patterns. 

  • The stability of a society, in contrast to social chaos and upheaval. 

How often have the words pecking order and social order occurred in a corpus of books? (source: Google Ngram Viewer )