What factors influence the point of view of an author of a document/source

The following factors can influence someone's point of view:

Past Experience — what someone is likely to notice or understand.

Culture — ethnicity, gender, country of origin, region of origin, language, socio-economic status, religion, political beliefs.

the  equal rights amendment  (era) states: "equality  of  rights  under the law shall not be denied or abridged by the united states or by any state on account of sex." congress first introduced the era in 1923, but the campaign for ratification took off in the 1960s during the  civil rightsmovement.

which statement explains one of the reasons world war 1 was so much more destructive than earlier conflicts