Constipated people tend to be obstinate, excessively concerned with hygiene, & inclined toward retaining possessions; diarrhoeic people tend to be careless, disorganized, & disposed to share their possessions with others

Consumer behaviour and the toilet: Research on expulsive and retentive personalities. Gianluigi Guido, Russell W. Belk, Cristian Rizzo, Giovanni Pino. Journal of Consumer Behaviour, https://doi.org/10.1002/cb.1709

Abstract: During the last five decades, a number of studies have attempted to draw from psychoanalytic theory to examine the relationship between evacuation disorders and a person's character. According to Freud's original conceptualization, early or harsh toilet training leads children to develop an anal retentive personality, characterized by the tendency to control their bowels as well as their material possessions; by contrast, liberal toilet training leads children to develop an anal expulsive personality, characterized by the tendency to excessively relieve faeces, as well as be being careless, messy, and inclined to dispose of old products and buy new ones. Although toilet training may not be responsible, these sets of traits do cohere. To empirically examine these hypotheses, we studied the personality traits and consumption habits of people suffering from different bowel disorders. By means of semistructured interviews, we analysed the personality characteristics, sociodemographic backgrounds, and peculiar consumption habits of people suffering from constipation and diarrhoeic syndromes. The results show that constipated people tend to be obstinate, excessively concerned with hygiene, and inclined toward retaining possessions, whereas diarrhoeic people tend to be careless, disorganized, and disposed to share their possessions with others. We discuss the theoretical and practical implications of these results and indicate avenues for future research.

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It is amazing, Freudianism doesn't die...