Question

Feigned smiles are initiated ________ abruptly and last for a ________ time than genuine smiles. more; shorter less; longer more; longer less; shorter

Answer 1

The answer : more; longer
This happen because feigned smiles is created in order to hide a certain negative emotions.
Since the face have to do contradictory expressions (from the intended emotion vs the actual emotion), the movement of the smile would seemed forced/abrupt.