twins: Burt's twin data

In alr4: Data to Accompany Applied Linear Regression 4th Edition

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)

Example output

Loading required package: car
Loading required package: carData
Loading required package: effects
lattice theme set by effectsTheme()
See ?effectsTheme for details.
   C IQb IQf
1 C1  82  82
2 C1  90  80
3 C1  91  88
4 C1 115 108
5 C1 115 116
6 C1 129 117

alr4 documentation built on May 2, 2019, 6:40 p.m.