Event-Related Changes in Personality Traits, Life Satisfaction, and Mental Health: Evidence from a 4-Year Longitudinal Study in sub-Saharan Africa

Emerging adulthood is a pivotal life phase that marks a period of identity formation and pronounced psychological changes (Arnett, 2007; Hutteman et al., 2014; Lüdtke et al., 2011; Roberts & Davis, 2016). It is a time of important life transitions and first-time experiences of significant events, such as entering the workforce, moving away from parents, or finishing education. These events have been theorized to catalyze changes in personality traits, life satisfaction, and mental health in emerging adulthood and beyond (Bleidorn et al., 2018; Brown & Harris, 1989; Cohen et al., 2019; Lucas, 2007). The Social Investment Principle (Lodi-Smith & Roberts, 2007; Roberts & Nickel, 2017), for instance, predicts that life events can lead to personality trait changes by eliciting changes in social roles. Becoming an employee may, for example, trigger increases in communion because it requires individuals to be polite, industrious, and friendly. Similarly, life events have been theorized to drive changes in well-being and mental health when they require individuals to adapt to new environmental circumstances, especially during emerging adulthood, a time characterized by instability (Beck & Bredemeier, 2016; Headey, 2010; Luhmann & Intelisano, 2018; Sheldon et al., 2013). Stressful events like unemployment or a relationship breakup may, for example, trigger decreases in people’s mental health and life satisfaction because they can negatively impact daily routines, reduce resources, and evoke negative emotions. Comprehensive meta-analyses support the developmental relevance of life events in emerging adulthood and beyond (Bühler et al., 2024; Haehner, Krämer, et al., 2025; Luhmann et al., 2012; March-Llanes et al., 2017; Paul & Moser, 2009). For example, entering the work force has been linked to increases in life satisfaction (d = 0.22) and conscientiousness (d = 0.28), whereas unemployment has been found to predict increases in depression (d = 0.50) and anxiety (d = 0.40). However, evidence on the effects of life events stems almost exclusively from high income, Western countries. For example, 96% of the studies included in the meta-analysis by Bühler et al. (2024) were conducted in Western countries, whereas studies from low- and middle-income countries including African countries were lacking. Likewise, contemporary meta-analyses on event-related changes in mental health, together, comprised only one study conducted in an African country (Haehner et al., 2024; Hühne et al., 2025; March-Llanes et al., 2017; Paul & Moser, 2009). Thus, there is a strong need to diversify research on life events. A thorough examination of event-related changes in samples from sub-Saharan Africa could advance psychological research in multiple ways. First, examining event-related changes in sub-Saharan Africa may help advance theoretical on personality traits, well-being, and mental health as currently available models provide limited insights into how cultural context influences changes in these variables (Bleidorn, 2024; Thalmayer et al., 2021). Second, investigating event-related changes in sub-Saharan Africa has applied relevance, as a better understanding of the conditions under which emerging adults in this region may thrive or struggle can inform contextually appropriate interventions. Third, sub-Saharan Africa is home to more of the world’s population than all Western countries combined and has a largely young population, with 70% under age 30 (United Nations, 2025). A better representation of this region thus is as an intellectual, ethical, and practical imperative. Fourth, as most psychological phenomena are influenced by cultural context, it may be a fallacy to assume that findings on event-related changes from Western countries generalize to other cultural contexts (Henrich et al., 2010; Kitayama & Salvador, 2024; McAdams & Pals, 2006). Although the mechanisms that are assumed to drive changes in personality traits, and well-being, and mental health may act similarly across cultural contexts (Haehner, Naudé, et al., 2025), there are also good reasons to assume that findings from Western countries may not generalize to African contexts. Existing research has, for instance, shown that the structure of personality traits and psychopathology differs across cultural contexts (Laher & Cheung, 2022). While most research in Western countries relied on the Big Five personality traits, the Big Two personality traits, agency (i.e., tendency to be sociable, surgent, confident, and fearless) and communion (i.e., tendency to be warm, respectful, industrious, and even-tempered), seem to work better across African countries (Thalmayer et al., 2025). Similarly, a unidimensional model to capture mental health problems tends to fit better in sub-Saharan Africa than the typically used internalizing-externalizing distinction (Hofmann et al., 2025). Furthermore, there are differences in social roles, economic resources, and familiar relationships that could shape how personality traits, life satisfaction, and mental health change in response to life events (Naudé & Esau, 2024; Uugwanga et al., 2025). For example, emerging adults in sub-Saharan Africa often face limited resources, high unemployment rates, and a strong need to support their families so that life events such as finishing education or starting full-time employment may have different meanings across cultural contexts (Naudé & Esau, 2024; Theron, 2013; Theron et al., 2021). Supporting this idea, there is preliminary evidence suggesting that education-related events are of particular relevance for emerging adults from sub-Saharan Africa and that the effects of life events on personality traits are stronger than in Western countries (Haehner, Naudé, et al., 2025). One reason why evidence on event-related changes in low and middle income countries is still limited is likely the methodological challenges involved in examining the effects of life events (Haehner, Krämer, et al., 2025). A rigorous investigation of event-related changes requires prospective longitudinal data with a large sample to examine changes before and after the event occurrence with sufficient statistical power (Bleidorn et al., 2020). Furthermore, multiple measurement occasions before and after the event occurrence are needed to investigate non-linear changes (Luhmann et al., 2014). The Africa Long Life Study (ALLS; Thalmayer et al., 2024) provides a unique opportunity to meet these requirements and thus contribute to a thorough understanding of event-related changes in sub-Saharan Africa. ALLS is a multi-year longitudinal study conducted with more than 3,000 emerging adults from Namibia, Kenya, and South Africa. Using this dataset to simultaneously investigate event-related changes in personality traits, life satisfaction, and mental health will allow us to (a) compare findings and effect sizes across outcomes and (b) get initial insights into the cross-cultural generalizability of event-related changes.