In "Word Focus" Glenn McClure writes:
In lesson 11 we looked at the message Paul conveyed when he spoke about being of one mind. In Romans 12:16 of today's lesson that phrase is encountered again. Only here Paul went on to discuss what must be done to keep that unity alive. One of the specific exhortations was to “condescend to men of low estate.” In its various forms the word translated low estate occurs thirty-four times in the New Testament. It is the normal word for humility, being translated that way in approximately half of its occurrences. Historically the literal meaning referred to something that was “low-lying.” But metaphorical meanings soon developed. In that way the word could refer to a person's social status or his emotional state. Mary used it in the Magnificat (Luke 1:48) to describe her social status. Paul described God as comforting “those that are cast down” (2 Cor. 7:6), a reference that at least includes the emotional aspect of the word. But most of the time the word has an ethical meaning that makes it the opposite of pride and arrogance.
Source: Building Christian Relationships: Adult Teacher's Insights, page 70.