Capturing the Motivational Impetus behind Lone-Actor Grievance-Fueled Violence: Developing and Validating a Scale Measuring Practical Relations-to-Self

Christopher Kehlet Ebbrecht, MSc, PhD Fellow at Department of Psychology and Behavioral Sciences, Aarhus University
Preben Bertelsen, Prof. dr., Department of Psychology and Behavioral Sciences, Aarhus University


Why do some people go on a killing spree all alone? Answering this question has never been more pressing than in the face of increasing attacks against civilians carried out by lone-actors (e.g. lone-actor terrorists, school shooters etc.). These attacks can be extremely lethal, and thus require urgent prevention (Bakker & de Graaf, 2010). Investigating how to do so, the literature emphasizes normal psychological mechanisms as risk factors of lone-actor radicalization, and the need to examine such factors in general populations (e.g. Clemmow, Schumann, et al., 2020). One particularly relevant factor is grievances , or experiences of being disrespected, that foster anger and creates a desire for revenge against one’s perceived perpetrators (McCauley & Moskalenko, 2017). Though highlighted as a key driver of, namely, lone-actor grievance-fueled violence (Clemmow, Gill, et al., 2020), little is known about how grievances are formed (Silver et al., 2019). Since uncovering the motivational impetus behind lone-actor grievance-fueled violence is vital in effective risk assessment and developing preventive interventions, we seek to answer this research question:

What is the core motivational mechanism underlying the grievance component of lone-actor grievance-fueled violence?


We hypothesize, that grievances are formed due to thwarting of so-called ‘practical relations-to-self’ in different ‘spheres’ of human life (Honneth, 1995): 1) basic self-confidence, shaped by love relations; 2) self-respect, formed by civil rights; and 3) self-esteem, fostered by social communities. As people’s degree of social worth depends on recognition of these three practical relations-to-self, disrespecting them “(…) thus carries with it the risk of bringing the identity of a person as a whole to a complete collapse” (Honneth, 1995, p. 132). Hence, disrespect leaves people in a state of social invisibility, and violence is a means of prompting others to take notice and thus regain recognition (Honneth & Margalit, 2001). Empirically, this is supported by experimental studies on ostracism, where people react aggressively to being ignored (Williams, 2007).

Hence, we examine the relationship between (thwarted) practical relations-to-self and the aggression inherent to lone-actor grievance-fueled violence.


As practical relations-to-self and aggression are mechanisms of normal psychological functioning, survey data based on general populations is particularly relevant for our research. To measure practical relations-to-self, we first develop and validate the novel ‘Relations-to-Self Scale’ (study 1). We second examine whether this scale predicts aggression and other known risk factors of lone-actor radicalization (study 2). Both studies are pre-registered on the Open Science Framework (OSF | Capturing the Motivational Impetus behind Lone-Actor Grievance-Fueled Violence: Developing and Validating a Scale Measuring Practical Relations-to-Self). All project materials (data, R analysis code etc.) will also be made publicly available at OSF.

Study 1

For each practical relation-to-self, we develop 10 items, which undergo peer deliberation and discussion in focus groups to enhance measurement validity. The scale is validated using two samples recruited from Prolific.

The first sample is used to validate the internal structure of the scale via Exploratory Factor Analysis. While appropriate sample size for factor analysis remains heavily debated, we follow the most conservative guideline on 1000 participants (Kyriazos, 2018). Items are assessed reliable at Cronbach’s alpha > 0.8 and valid at item loadings > 0.4.

Using the second sample, we validate the scale via Confirmatory Factor Analysis by the following guidelines (Kline, 2012): Comparative fit index (CFI) ≥ 0.9, standardized root mean square residual (SRMR) ≤ 0.08, and root mean square error of approximation (RMSEA) ≤ 0.08. We expect a one-factor structure capturing overall relations-to-self (H1.1a), and a three-factor structure tapping each relation-to-self (H1.1b). We also test convergence validity using the needs-threat scale (Zadro et al., 2004) and Sheldon Needs Scale (Sheldon et al., 2001), and predictive validity using the Satisfaction with Life Scale (Diener et al., 1985). We expect that the Relations-to-Self Scale correlate significantly (p<0.05) with both need-scales (H1.2a), yet represent a distinct construct (r2 ≥ 0.1) (H1.2b), and thwarted practical relations-to-self to be significantly (p<0.05) correlated with lower life satisfaction (H1.3). Using power analysis via G*Power with an alpha of 0.05, power of 0.95 and a small effect size (p = 0.1) as conventional in personality research (Gignac & Szodorai, 2016), the required total sample size for a two-tailed t-test is 1289 participants.

Study 2

Using our novel scale, we test whether thwarted practical relations-to-self correlate significantly (p<0.05) with higher levels of aggression (H2) via a sample recruited from Prolific. To measure aggression, we use the revised Aggression Questionnaire (Bryant & Smith, 2001), capturing 1) physical aggression, 2) verbal aggression, 3) anger, and 4) hostility.

As covariates, we include known risk factors of lone-actor radicalization, i.e. propensities that increase individuals’ disposition to engage in mass violence (Clemmow, Bouhana, et al., 2020). Specifically, we include the Short Dark Triad (SD3) (Jones & Paulhus, 2014); Ryff’s Scales of Psychological Well-being (Ryff & Keyes, 1995); the Sense of Coherence Questionnaire (Antonovsky, 2012); the Life Attachment Scale (Bertelsen & Ozer, 2018); the Need for Closure Scale (Webster & Kruglanski, 1994); a self-uncertainty measure (Rast et al., 2012); the Militant Extremist Scales (Stankov et al., 2010); and the mechanisms of moral disengagement scalerevised (Bertelsen & Ozer, 2018).

For a two-tailed t-test, the required total sample size calculated via G*Power (alpha = 0.05, power = 0.95, and small effect size (p = 0.1)) is, likewise, 1289 participants.


Participants are ensured anonymity and asked to provide informed content prior to study involvement. Participants are informed they can withdraw consent and end the survey any time.


In all surveys, we wish a nationally representative UK/US sample. Participants receive an hourly rate of £7.50 as suggested by Prolific. Based on Qualtrics estimations, the response time for each survey is 5, 7 and 20 minutes, respectively. The total price is £9,135.09 (including 33% service fee and VAT).

Publication and dissemination

For each study, we submit a manuscript to a journal supporting open science, e.g. Perspectives on Terrorism . We also apply for presenting our findings at the Nordic Conference on Violent Extremism in 2022. To insure practical impact of the project, we will communicate our results to institutions and practitioners working with anti- and de-radicalization, e.g. the Danish Centre for Prevention of Extremism and the European Commission Radicalisation Awareness Network .


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