Frankly, personality “type” is not the ideal nomenclature here; personality “clusters” might be more accurate. Paper co-author William Revelle (Northwestern University) bristles a bit at the very notion of distinct personality types, like those espoused by the hugely popular Myers-Briggs Type Indicator. Revelle is an adamant “anti-fan” of the Myers-Briggs, and he is not alone. Most scientists who study personality prefer to think of it as a set of continuous dimensions, in which people shift where they fall on the spectrum of various traits as they mature.