Unicorns, snarks, and personality types: A review of the first 102 taxometric studies of personality

Abstract

Objective

The default assumption among most psychologists is that personality varies along a set of underlying dimensions, but belief in the existence of discrete personality types persists in some quarters. Taxometric methods were developed to adjudicate between these alternative dimensional and typological models of the latent structure of individual differences. The aim of the present review was to assess the taxometric evidence for the existence of personality types.

Method

A comprehensive review yielded 102 articles reporting 194 taxometric findings for a wide assortment of personality attributes.

Results

Structural conclusions differed strikingly as a function of methodology. Primarily older studies that did not assess the fit of observed data to simulated dimensional and typological comparison data drew typological conclusions in 65.2% (60/92) of findings. Primarily newer studies employing simulated comparison data supported the typological model in only 3.9% (4/102) of findings, and these findings were largely in the domain of sexual orientation rather than personality in the traditional sense.

Conclusions

In view of strong Monte Carlo evidence for the validity of the simulated comparison data method, it is highly likely that personality types are exceedingly scarce or non‐existent, and that many early taxometric research findings claiming evidence for such types are spurious.

Key words:

• categories
• dimensions
• personality
• taxometrics
• types
• typology