They are not aware of each other because usually they are sesperate and don't live together.
Various areas of social influence
Social influence is ubiquitous in human societies. It takes a wide variety of forms, including obedience, conformity, persuasion, social loafing, social facilitation, deindividuation, observer effect, bystander effect, and peer pressure. ... Since then, social influence has fascinated scholars in various fields.
Yes genetic testing can maintain confidentiality. <span />
