Gift of Gab is a companion perk in Fallout 4.
To gain the perk, the Sole Survivor has to reach maximum affinity with Piper.
The player character gains double the XP value when persuading other people or when discovering new places.
Behind the scenes
The "Gift of Gab" refers to the Irish legend of kissing the Blarney Stone. The legend states that the kisser of the stone is granted the gift of the gab, that is greater eloquence or flattery.