  When interacting with others in our everyday life, we prefer the company of
those who share with us the same desire of closeness and intimacy (or lack
thereof), since this determines if our interaction will be more o less
pleasant. This sort of compatibility can be inferred by our innate attachment
style. The attachment style represents our characteristic way of thinking,
feeling and behaving in close relationship, and other than behaviourally, it
can also affect us biologically via our hormonal dynamics. When we are looking
how to enrich human-robot interaction (HRI), one potential solution could be
enabling robots to understand their partners' attachment style, which could
then improve the perception of their partners and help them behave in an
adaptive manner during the interaction. We propose to use the relationship
between the attachment style and the cortisol hormone, to endow the humanoid
robot iCub with an internal cortisol inspired framework that allows it to infer
participant's attachment style by the effect of the interaction on its cortisol
levels (referred to as R-cortisol). In this work, we present our cognitive
framework and its validation during the replication of a well-known paradigm on
hormonal modulation in human-human interaction (HHI) - the Still Face paradigm.
