Conversion, Deconversion, and Radical Personality Change

Conversion, Deconversion, and Radical Personality Change July 17, 2023
Photo by Joel Furches

“William James (1901) in his famous study, Varieties of Religious Experiences, understood conversion to be a kind of healing. The healing, as James understood it, was that of a sick, divided soul that sought healing and unification of personhood in religion …modern scholars are skeptical about James’ claim that a conversion experience can change a person’s personality.”

-Marriott, 2023

While the trope of “seeing the light” or “finding Jesus” has somewhat fallen out of vogue, it is nevertheless true that there exists a longstanding and storied history behind the concept that once one becomes religious, one’s behaviors and personality radically change, sometimes overnight. As deconversion research continues to rise in interest and examination, a similar question regarding personality changes upon deconversion likewise arises. But is there any truth to the former or evidence for the latter?

Deconverts’ Personalities

One group of researchers who explored this question did it from the angle of socialization. Specifically, they asked “Do [deconverts] resemble socialised believers, due to their prior religious education, or socialised nonbelievers given their current nonbelief?” (Saroglou et al., 2020)

This primary question leads to several secondary questions. Did deconverts always have behaviors and personalities more similar to nonbelievers? If they did, this may explain why they eventually left a group with whom they were dissimilar and joined a group whose behaviors matched their own. Or, more to the point of this article, did the personality of the deconvert change at some point?

What the researchers found was a mixed bag. The deconverts had cultural values and a drive for personal autonomy which resembled their unbelieving peers. However, their preference for the transcendent was somewhat higher than their non-believing peers (although not as high as those who had remained believers).

As interesting as that is, it does not answer the larger question of “did their personalities change at some point?” For the answer to that, we need to examine a longitudinal study.

The Longitudinal Study

Longitudinal studies follow a person or group of people over an extended period of time in order to track changes in those people. If we had access to a study which followed groups of people as they converted or deconverted, it would be helpful in answering the question of does a change in religion cause a change in personality? Fortunately for us, we have access to just such a study.

Titled “Religion and the Development of Character: Personality Changes Before and After Religious Conversion and Deconversion,” this study was conducted in 2021, and followed 31,604 participants from New Zealand, who identified as either recently converting or deconverting, over a period of 9 years. Because of the longitudinal nature of the study, participants entered and exited over time, making the demographic charting complex.

The Big Five

Nevertheless, the researchers found some fascinating results. Prior to discussing the results, however, something needs to be clarified. When researchers study personality, they almost exclusively use a scale of measurement simply called “The Big Five.” This scale has a long history of development, and reigns as the golden standard in psychology for personality measurement. It includes the following:

  • Openness – Seeking new experiences, creativity, and imagination. As opposed to conventional thinking and static behaviors.
  • Conscientiousness – organization, discipline, and reliability. As opposed to impulsivity and erratic behavior.
  • Agreeableness – Empathetic, considerate, and cooperative. As opposed to competitive, passive-aggressive, or cynical.
  • Extraversion – Sociable and confident. As opposed to introverted.
  • Neuroticism – Anxiety, depression, and negative emotions. As opposed to positive and emotionally stable.


In addition to the Big Five, researches also rated participants on a scale of Honesty and Humility.


The first result discussed by the researchers was that those individuals who converted to religion didn’t evidence any sort of personality changes prior to conversion. After conversion, however, personality changes were very evident. The specific changes noticed included an increase in Honesty-Humility, Conscientiousness, and Neuroticism. This somewhat confirms the conventional wisdom that conversion actually changes a person’s personality, and undermines a bit of the skepticism mentioned above.

Perhaps more interesting, however, were the results for deconversion. For those individuals who left religion to join the ranks of the atheists, a personality change was evident as well. However, in this case, the personality change began to occur prior to the deconversion. This answers the question raised by the first study we examined above. The person neither deconverts because their personality was more similar to atheists all along, nor does their personality change because of the deconversion. The personality change appears to occur prior to or simultaneous to the deconversion process. But what do these changes look like? According to the study, prior to deconversion, increases were noted in Honesty-Humility and decreases in Agreeableness were seen.

Researchers concluded that conversion does initiate personality changes, and the most significant of these included an increase in modesty and greed-avoidance.


The above mentioned study was surprising insofar as it somewhat confirmed the classic notion that coming to religion changes a person. The degree of the change and the permanence of the change is still up in the air. We know the change lasts at least nine years, the duration of the study.

More important is the find that deconversion evidences a personality change before the person deconverts. This raises a number of questions regarding cause and effect, which are worth examining in future studies.

One elephant which remains in the room is the finding regarding an increase in Neuroticism after conversion. The larger corpus of religious research indicates that religion has a stabilizing effect on emotional wellbeing, and tends to foster mental health. Which raises the question of how can this study be correlated with the seemingly contradictory finds of other research? For this further study may be required. However one possible explanation would be the cultural context. This study was conducted in New Zealand. Religious rates in New Zealand are relatively low, with about half the population claiming no religion at all. A conversion to religion in a largely secular culture potentially would cause a period of identity crisis and isolation, which may explain the neuroticism. However, the study does not investigate this.

Stronge, S., Bulbulia, J., Davis, D. E., & Sibley, C. G. (2021). Religion and the Development of Character: Personality Changes Before and After Religious Conversion and Deconversion. Social Psychological and Personality Science, 12(5), 801–811.
Saroglou, V., Karim, M., & Day, J. M. (2020). Personality and values of deconverts: A function of current nonbelief or prior religious socialisation? Mental Health, Religion & Culture, 23(2), 139–152.

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