Nytonial

Yes its because they are (assumed) to be at a steeper angle of incidence. As long as your plane is of stable design, when pitching up (to the extreme) the front cannards are at higher angles than the wing and so loose areodynamical properties first, meaning they can no longer add more pitch to the planes heading. This leaves a craft with only standard wings, considerably further back than usual, aerodynamic drag and momentum then snap your plane back to level flight. Picture the reverse, standard elivators, while pitching up, the wings are at a higher angle than the elivators, the wing stalls first and leaves the elivators able to add more pitch. The centre of lift is also moved further back though, so there is some stability in this, only it can still be "steered" out of level flight, wheras the cannards in stall will quickly point back to level flight.