How might psychologists use individual differences versus universal principles to understand a phenomenon like romantic attraction between two people

As per psychology, Romantic appeal is a cognitive reaction which most individuals undergo at one time or another, contributing to a preference for a romantic connection with the person receiving. Even if they do not feel physical desire, many monogamous individuals experience romantic appeal.

  However, as per the universal principles Physical appearance, proximity, resemblance, and mutuality are included: Physical appearance: Study indicates that physical desirability mostly defines romantic interest. Individuals are more drawn to partners that they deem to be visually desirable in the initial phases of relationships.

world war i had a devastating effect on german-americans and their cultural heritage. up until that point   german-americans, as a group, had been spared much of the discrimination, abuse, rejection, collective mistrust experienced by so many different racial and ethnic groups in the history of the united states. indeed, over the years, they had been viewed as a well integrated and esteemed part of american society. all of this change with the outbreak of war.