Abstract
The literature was reviewed to investigate the origins of the traits of “agreeableness” and “cooperativeness”, which seem to have similar implications. The literature suggested that these traits were influenced by genetic as well as environmental factors. These traits were related to temperaments of social-bonding formation and its maintenance (e.g., affiliation) and self-regulation. Affiliation, empathy, which seemed to be closely related to agreeableness, cooperativeness, and social-bonding formation and its maintenance all had neurobiological bases. These bases could be a part of the genetic origins of agreeableness and cooperativeness. Further investigations are necessary regarding the relationship among the components, formation processes as personality traits, and the environmental origins of agreeableness and cooperativeness. It is also necessary to reexamine the content of the scales measuring these traits.
