aggression vs constraint

aggression

noun
  • Hostile or destructive behavior or actions. 

  • The practice or habit of launching attacks. 

  • The act of initiating hostilities or invasion. 

constraint

noun
  • An irresistible force or compulsion. 

  • A condition that a solution to an optimization problem must satisfy. 

  • A linkage or other restriction that maintains database integrity. 

  • The repression of one's feelings. 

  • Something that constrains; a restriction. 

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