Date of Award

May 2021

Document Type


Degree Name

Doctor of Philosophy (PhD)


Industrial-Organizational Psychology

Committee Member

Fred Switzer

Committee Member

Patrick Rosopa

Committee Member

Grigori Yourganov

Committee Member

Claudio Cantalupo


This study replicates and then refutes portions of an article published in Nature by Gerlach, Farb, Revelle, & Nunes Amaral (2018) on personality clusters. The central claim of the current study is that the clusters were actually biases in the data, based on central tendency and social desirability biases. We find that with proper preprocessing of our data, that all personality clusters found in the Gerlach et al. (2018) study cease to exist as anything but random noise. The interpretation of these findings is that careless responding, response styles, and characteristics of Likert scale style data can lead to artificial clustering, leading to improper interpretation of the frequency of occurrence of certain arrangements of personality traits. The implications of these findings are that unsupervised machine learning approaches can be especially useful in personality research, but misuse of these approaches can lead to misleading results.



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