Changes in personality are often modeled linearly or curvilinearly. It is a simplifying-yet untested-assumption that the chosen sample-level model form accurately depicts all person-level trajectories within the sample. Given the complexity of personality development, it seems unlikely that imposing a single model form across all individuals is appropriate. Although typical growth models can estimate individual trajectories that deviate from the average via random effects, they do not explicitly test whether people differ in the forms of their trajectories. This heterogeneity is valuable to uncover, though, as it may imply that different processes are driving change. The present study uses data from four longitudinal data sets (N = 26,469; Mage = 47.55) to empirically test the degree that people vary in best-fitting model forms for their Big Five personality development. Across data sets, there was substantial heterogeneity in best-fitting forms. Moreover, the type of form someone had was directly associated with their net and total amount of change across time, and these changes were substantially misquantified when a worse-fitting form was used. Variables such as gender, age, trait levels, and number of waves were also associated with people's types of forms. Lastly, comparisons of best-fitting forms from individual- and sample-level models indicated that consequential discrepancies arise from different levels of analysis (i.e., individual vs. sample) and alternative modeling choices (e.g., choice of time metric). Our findings highlight the importance of these individual differences for understanding personality change processes and suggest that a flexible, person-level approach to understanding personality development is necessary. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

中文翻译：

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人格特质轨迹形式的个体差异。


性格的变化通常是线性或曲线建模的。这是一个简化但未经测试的假设，即所选的样本级模型形式准确描述了样本中的所有人员级轨迹。鉴于人格发展的复杂性，对所有个体强加单一模型形式似乎不太可能是合适的。尽管典型的增长模型可以通过随机效应估计偏离平均值的个体轨迹，但它们并没有明确测试人们的轨迹形式是否不同。不过，揭示这种异质性很有价值，因为它可能意味着不同的过程正在推动变革。本研究使用来自四个纵向数据集 （N = 26,469;Mage = 47.55），以实证方式检验人们在最适合其大五人格发展的模型形式中的差异程度。在数据集中，最佳拟合形式存在很大的异质性。此外，某人的表单类型与他们随时间变化的净变化量和总变化量直接相关，当使用拟合较差的表单时，这些变化被严重错误量化。性别、年龄、特征水平和波数等变量也与人们的形态类型有关。最后，对个体和样本水平模型的最佳拟合形式的比较表明，不同层次的分析（即个体与样本）和替代建模选择（例如，时间指标的选择）会产生相应的差异。我们的研究结果强调了这些个体差异对于理解人格变化过程的重要性，并表明需要一种灵活的、个人层面的方法来理解人格发展。 （PsycInfo 数据库记录 （c） 2024 APA，保留所有权利）。