- "She is able to tell if a person is lying."
- ―Entry on Maggie's gift [src]
Maggie can sense if a person is lying to her or to someone else.
Maggie can sense a lie by being in close proximity to someone. A person didn't have to speak for her to know if he or she was behaving in a way contrary to their beliefs. If anyone misrepresented themselves in either appearance or action, Maggie could feel it automatically.
However this also has a side effect, as any kind of deception made her physically uncomfortable.
When Maggie was human, she always knew when a person was lying with their words, compelling her to always point out the lie. This made others feel uncomfortable around her as they could never lie in her presence, prompting her parents to leave her behind when they immigrated to America.
- "... She had a gift for knowing when she was being lied to, and her verdicts were never contested."
- ―Bella's description of Maggie's talent.[src]
- "Charles can sense when someone is lying to him."
- ―Entry on Charles's gift[src]
Charles can sense whether a person is lying to him. It has not been explained how different from Maggie's this gift is, but it appears to be less pronounced than hers.
- "It is not what I see, but what I feel. Garrett said they have ways of knowing lies. I, too, know when I am hearing the truth, and when I am not."
- ―Charles's description of his power.[src]
When Charles and his mate, Makenna, arrive in Forks on behalf of the Volturi, Charles determines that the Cullens are in fact innocent, being falsely blamed for a crime they did not commit.
- Aro's ability of tactile telepathy allows him to read people's minds and determine if they were telling the truth as well as access to every thought they ever had.
- Edward Cullen's ability of telepathy allows him to read people's minds to secure if they were telling the truth about something.