One Hundred Years of Social Psychology Quantitatively Described

This article compiles results from a century of social psychological research, more than 25,000 studies of 8 million people. A large number of social psychological conclusions are listed alongside meta-analytic information about the magnitude and variability of the corresponding effects. References to 322 meta-analyses of social psychological phenomena are presented, as well as statistical effect-size summaries. Analyses reveal that social psychological effects typically yield a value of r equal to.21 and that, in the typical research literature, effects vary from study to study in ways that produce a standard deviation in r of.15. Uses, limitations, and implications of this large-scale compilation are noted.