Are people more likely to trust people who are "like" them? A recent article published in the Journal of Experimental Social Psychology suggests that this is the case. The article suggests that people are less likely to trust people with heavy accents. In the study, Shiri Lev-Ari and Boaz Keysar set up an experiment where they had 55 English speaking Americans judge the truthfulness of several trivia statements read by people with varying accents. The participants were more likely to believe statements read by English speaking Americans than individuals with mild and moderate accents.
Accents may be one factor that affects whether someone will trust a person. Other factors may include how a person dresses and how they act. One of Michael Westen's infamous and clever spy suggestions in Burn Notice is to act like your target, as this will most likely help you gain your target's trust. "Every kid who ever went to a new school knows the secret to fitting in: copy everyone else. Spies do the same thing. Tailor their wardrobe, their movement, and their behavior to imitate their targets- all the little things that say, I'm your kind of guy." (From "Fearless Leader")