Description

The Burt data frame has 27 rows and 4 columns. The “data” were simply (and notoriously) manufactured. The same data are in the dataset “twins" in the alr3 package, but with different labels.

Usage

Format

This data frame contains the following columns:

IQbio

IQ of twin raised by biological parents

IQfoster

IQ of twin raised by foster parents

class

A factor with levels (note: out of order): high; low; medium.

Source

Burt, C. (1966) The genetic determination of differences in intelligence: A study of monozygotic twins reared together and apart. British Journal of Psychology 57, 137–153.