Nope, wisdom drain is correct. Actual lamia matriarchs can do this at will. This lamia commoner racial trait is essentially a weaker version of the lamia matriarch’s wisdom drain ability. Admittedly, it is one of the stronger alternate racial traits a lamia commoner can take, which is why it replaces two standard racial traits – lamia immunities and weapon familiarity.

Of course, since alternate racial traits are a purely optional part of the game, a GM is free to disallow this one if he feels it is too powerful