Meta-analysis in psychology: a bibliometric study

Meta-analysis refers to the statistical methods used in research synthesis for combining and integrating results from individual studies. The present study draws on the strengths of bibliometric methods in order to offer an overview of meta-analytic research activity in psychology, as well as to characterize its most important aspects and their evolution over time. A total of 2,874 articles published in scientific journals were identified and standard bibliometric indicators (e.g., number of articles, productivity by country, and national and international collaborations) and laws (e.g., Price’s and Lotka’s law) were applied to these data. The results suggest a clear upward trend not only in the number of articles published since the 1970s (with a peak of productivity in 2010), but also in both the number of authors by article ( $ \bar{x} = 2. 7 5 $ , SD = 1.53) and internationalization, especially since the 1990s. The interest in meta-analysis extends to many authors (n = 5,445), countries (n = 44) and scientific journals (n = 394), as well as to several areas of psychology that mostly fit a growing exponential model. In future studies it would be interesting to explore the citing behaviour and patterns in the meta-analysis literature.