A data frame containing data collected in the mid 20th century by Cyril Burt from a study tracked down identical twins who were separated at birth: one child was raised in the home of their biological parents and the other in a foster home. In an attempt to answer the question of whether intelligence is the result of nature or nurture, both children were given IQ tests.
Format
A data frame with 27 observations on the following 2 variables.
- foster
IQ score of the twin raised by Foster parents.
- biological
IQ score of the twin raised by Biological parents.
Examples
library(ggplot2)
library(dplyr)
library(tidyr)
plot_data <- twins |>
pivot_longer(cols = c(foster, biological), names_to = "twin", values_to = "iq")
ggplot(plot_data, aes(iq, fill = twin)) +
geom_histogram(color = "white", binwidth = 5) +
facet_wrap(~twin) +
theme_minimal() +
labs(
title = "IQ of identical twins",
subtitle = "Separated at birth",
x = "IQ",
y = "Count",
fill = ""
)
