  We present a storytelling robot, controlled via the ACT-R cognitive
architecture, able to adopt different persuasive techniques and ethical stances
while conversing about some topics concerning COVID-19. The main contribution
of the paper consists in the proposal of a needs-driven model that guides and
evaluates, during the dialogue, the use (if any) of persuasive techniques
available in the agent procedural memory. The portfolio of persuasive
techniques tested in such a model ranges from the use of storytelling, to
framing techniques and rhetorical-based arguments. To the best of our
knowledge, this represents the first attempt of building a persuasive agent
able to integrate a mix of explicitly grounded cognitive assumptions about
dialogue management, storytelling and persuasive techniques as well as ethical
attitudes. The paper presents the results of an exploratory evaluation of the
system on 63 participants
