I worked many years ago with a young woman who went out of her way to make people feel welcome and comfortable in the office. She was perpetually cheery, jocular and friendly. She went out of her way to remember birthdays, celebrate successes and turn the office into a family like environment.
She had Referent Power. But we didn’t call it that back in those days. She had what we called Likeability. Everyone liked her.
And that Likeability moved mountains. She could get people to drop what they were doing and bend to her smallest need just in an attempt to please her. That’s the power of Likeability.
The great thing about Referent Power or Likeability is that no one minds it as a source of power (except for people who aren’t likeable.) People might reject Positional Power, dread Coercive Power, or fear Expert Power but they rarely reject Referent Power.
The moral of the story is exactly like your mother told you. If you can’t say anything nice, don’t say anything at all.