This paper explores the relationship between the way people think and what they do, among a recently migrated urban ethnic group. The hypothesis is that people will seek assistance (housing, employment, friends) from other people whom they perceive as most similar to themselves. The paper compares two sets of data in an attempt to examine this relationship. Both cognitive and behavioral data on social interactions were collected from Navajo women in Los Angeles, California. The data indicate that urban Navajo women tend to establish their social assistance networks based on some of the underlying dimensions of their cognitive classifications of the urban social world, but that in other respects their behavior diverges from the expected.