Gravity is a truth of a fundamentally different order from notions like love, depression or personality. It causes apples to fall on people's heads, while concepts like personality are just convenient, relatively woolly psychological constructs we use to talk about what it is to be human. Fuzziness is understandable - maybe even desirable. It may more faithfully reflect the workings of the human mind, which are harder to capture in hard scientific terms than the physical world. Unlike the mature field of physics, psychology is a young science. Even the most basic psychological truths are open to debate. Unlike current theories in quantum physics, most people have an opinion on new psychological theories. Psychology is easier to render understandable and is closer to the layperson's personal experience. Consequently, the public is regularly assailed by vulgarised versions of fresh psychological 'breakthroughs'. One smash hit among the recent crop vying to reach household-name status is emotional intelligence. The term was voted by the American Dialect Society one of the most popular new phrases to enter the English language in the last decade of the 20th century. As a scientific concept, it was created by Peter Salovey and Jack Mayer. The concept reflects an emerging shift in thinking about intelligence in general and how it can be measured. Intelligence is traditionally thought of as a single overall ability, best measured by a select group of skills. Being good at abstract thinking shows a person is bright, while being a good swimmer or cook does not. But many experts now talk in terms of a constellation of intelligences, including creative, practical and social. Emotional intelligence also ties in with the latest thinking about the nature of human passion and reason - no longer seen as opposites. Instead of being regarded as chaotic, random and immature, emotions are now seen as adaptive responses that actually help people organise their behaviour. Having the 'intelligence' to be in touch with ones own emotions and with other people's, therefore, is a distinct advantage in all spheres of life. Emotional intelligence is essentially about systemising and using phenomena that may otherwise remain at an instinctive level: perceiving and identifying emotions, using emotions to facilitate thought, understanding emotions and managing or controlling them. The recent academic Handbook of Emotional Intelligence sees potential for schools, businesses and at home. Being able to measure emotional intelligence is, therefore, crucial. If it can be harnessed in any systematic way, it must be possible to measure it. Yet there is no agreed-upon method to do so. This is a serious drawback. If changes based on emotional intelligence are introduced into a workplace, for example, minimum best practice dictates that the results ought to be testable. As noted by Richard Roberts, of the Centre for New Constructs in the US, psychological science is frustratingly hard to do. This is particularly true when it comes to how individuals differ. The whole area gets harder still when it comes to looking at how people feel, rather than how they think. For some, the very idea of measuring emotion is missing the point entirely. Yet the science of psychology depends on just this sort of exercise. Emotional intelligence popped up in a messy research area - it overlaps awkwardly with theories of personality and social skills. Whether this is a sign of inventiveness or lack of rigour is a matter of opinion. But the fact remains that the only way any of these theories can seriously claim to distinguish itself from practices like astrology and crystal-ball reading is to call on psychological research. Theories are generally based on a carefully selected body of studies. Most evidence for new constructs comes from new experiments. Additional 'evidence' is then gleaned from reinterpreted previous work. What separates psychological theories from each other, aside from the attractiveness of the theory and its proponents, is an even tighter selection and interpretation of findings. Clearly, everybody possesses a particular array of expertise in the emotional skills that life demands. This is recognised in home-spun theories of character. Does the concept of emotional intelligence represent any progress in this domain? That is yet to be seen, if we judge it by its own scientific standards. Maybe it will go the way of 'significant other' or 'A type personality' - notions so attuned to their times that they fall out of fashion, if not circulation. Jean Nicol is a psychologist specialising in issues of cultural identity and change in an era of globalisation everydaypsychologist@yahoo.com