A recent study suggests that friendly workers are more productive workers as well. It seems friendly workers tend to tune-in to nonverbal cues from people they work with and gather more information about the context of interactions. Consequently they tend to be more productive in accomplishing tasks.
The study’s author says, in contrast to other cultures, the US tends to encourage emotional distance in the workplace. Relationships play a bigger role in business transactions in some other countries.
So, you Relationship Managers, keep on smiling.