Regardless of whether the focus is on the trait or ability
dimension, a challenge with EI is to determine the set of
measurable manifestations, which explains the large quantity of
models that have emerged over the years. A critique levelled
against Bar-On’s model is that it is over-inclusive, comprising a
large quantity of social and emotional skills that determine how we
understand ourselves and others, how we relate to others, and how
we cope with daily activities [8]. In particular, it has been
suggested that some of these factors are too broad and
conceptually unrelated to EI [9–11]. In order to improve our
understanding of this construct, researchers have emphasized the
necessity to explore its biological basis [12–15]. To date, however,
the role of biological factors has not been examined across the EI
literature [9,14,16]. The present study provides a starting point for
research in this promising area, seeking to identify biological
factors implicated in typical-performance or trait EI.