Psychologist hans eysenck used factor analysis to identify patterns of traits and found that personality could best be described in terms of just three major dimensions.

forty niners migrated west due to gold discovery in california and it the west was a new place for hope this : )

explanation:

the factors that the economies of the muslim empires prosper were:

1- land trade routes-located between three continents  

2- sea trade routes

trade contributed to the spread of muslim empires, and with that islamic culture led to a growing feeling of internationalism resulted in the transfer of technology, science, and other cultural forms.