For searches for cross-cultural topics in developmental and social psychology, ProQuest PsycINFO gives results most closely targeted to human psychology; Web of Science offers useful journal groupings through the Journal Citation Reports.
How do you start? Consider starting with a Concept Map like the one from class:

It helps to have the Boolean operators handy:

and to use the Truncation Operator * :

Finally, many database environments such as ProQuest support PROXIMITY SEARCHING.
