twins {alr4}

Burt's twin data

Description

The given data are IQ scores from identical twins; one raised in a foster home, and the other raised by birth parents.

Format

This data frame contains the following columns:

C

Social class, C1=high, C2=medium, C3=low, a factor

IQb

biological

IQf

foster

Source

Burt, C. (1966). The genetic estimation of differences in intelligence: A study of monozygotic twins reared together and apart. Br. J. Psych., 57, 147-153.

References

Weisberg, S. (2014). Applied Linear Regression, 4th edition. Hoboken NJ: Wiley.

Examples

head(twins)