The Emotional Intelligence (EI) research literature is diverse, complex and riddled with controversy concerning the labels and taxonomy used to define emotional intelligence, and the methodology used to assess people against it. This thesis outlines these and other challenges that face researchers and practitioners, offering a pathway through them that respects those factors and features that subject-matter experts (SME) agreed upon. It also addresses many of the criticisms and disagreements acrossthe EI research community. This is a theoretical study that draws on work from the last one hundred years. It proposes a generic Emotional Intelligence model (EmotionIntell), also referred to in this thesis as the ‘e’ factor. It arguesthat the EI construct has to centre on abilitiesto enable it to be classified as an intelligence. However, it must respect and integrate the value and moderating effect of traits, amongst other individual differences, as context is crucial to EI performance. This research asserts that an EI model that qualifies as an intelligence did not, until this point, exist. The SMEs confirm this, along with other agreements relating to EI that are deemed significant; these findings are offered as a dataset, to support future research. This research delivers a generic model, that is not tied only to leadership, well-being or teamwork. It is also value-neutral (as much as this is possible) and does not dictate a moral code to the user, though the author hopes that its primary use will be to support well-being and constructive behaviour. It provides a framework that captures the idea that ability is about guiding appropriate thinking, behaviour, and actions, towards goals while respecting specific contexts. The thesis also proposes assessment approaches that will guide the future development of assessment instruments, thereby providing an IQ-type measure of emotional intelligence, against this EI model, to enable subsequent reliability and validity analysis.