Effect sizes from one hundred years of social psychology
A total of 474 effect sizes from meta-analyses from social psychology during one hundred years extracted from the study by Richard et al. (2003) into a tab-separated CSV file.
Thanks to @richarddmorey we now have year as well.
originalorderis the order of the effect size as in Richard et al. (2003).
fieldis one of 18 research fields the effect sizes are grouped into, as in Richard et al. (2003).
descriptionis a short description of the effect size in question.
kis the number of studies.
ris the mean effect size (Pearson's r).
sdis the standard deviation of the mean effect size. This is the only field with missing values, denoted by
documentnumberrefers to the document number of the specific meta-analysis. See appendix in Richard et al. (2003).
referenceis the reference to the specific meta-analysis.
yearis when the meta-analysis was published (extracted from reference).
- Expectancy effects
- Gender roles
- Group processes
- Health psychology
- Helping behavior
- Intergroup relations
- Nonverbal communication
- Social cognition
- Social influence
Import into R
df <- read.csv("https://raw.githubusercontent.com/peterdalle/effectsizes/master/soc-psych.tsv", header=TRUE, sep="\t", stringsAsFactors=FALSE) df$field <- factor(df$field) # What is the mean effect size from all meta-analyses? mean(df$r) # What is the mean effect size from all meta-analyses in aggression research? mean(subset(df$r, df$field == "Aggression")) # Histogram of all effect sizes. hist(df$r, breaks = 30) library(tidyverse) # Reproduce graph in Richard et al. (2003), but use density instead. df %>% ggplot(aes(r)) + geom_density(fill="grey") + scale_x_continuous(limits=c(0, 1), breaks=seq(0, 1, 0.1)) + theme_minimal() + labs(title="Magnitude of meta-analytic effect sizes in social psychology", x="Mean correlation coefficient", y="Density") # Plot all effect sizes by field. df %>% ggplot(aes(year, r, color=factor(field))) + geom_point() + theme_minimal() + labs(title="All effect sizes by year", color="Field", x="Field", y="Effect size (r)") # Plot mean effect size by year. df %>% group_by(year) %>% summarize(meanr = mean(r)) %>% ggplot(aes(year, meanr)) + geom_point() + theme_minimal() + labs(title="Mean effect size by year", x="Year", y="Effect size (r)")
Import into Python
import pandas as pd import numpy import matplotlib.pyplot as plt data = pd.read_csv("https://raw.githubusercontent.com/peterdalle/effectsizes/master/soc-psych.tsv", sep="\t") # What is the mean effect size from all meta-analyses? numpy.mean(data["r"]) # Histogram. plt.hist(data["r"], bins="auto") plt.title("Magnitude of meta-analytic effect sizes in social psychology") plt.show()
Richard, F. D., Bond, C. F., & Stokes-Zoota, J. J. (2003). One Hundred Years of Social Psychology Quantitatively Described. Review of General Psychology, 7(4), 331–363. https://doi.org/10.1037/1089-26126.96.36.1991