iqdat {umx} | R Documentation |
Twin data: IQ measured longitudinally across 4 ages.
Description
Measures of IQ across four ages in 261 pairs of identical twins and 301 pairs of fraternal (DZ) twins. (see details). It is used as data for the [umxSimplex()] examples.
Usage
data(iqdat)
Format
A data frame with 562 rows (twin families). Nine measures on each twin.
Details
zygosity Zygosity (MZ or DZ)
IQ_age1_T1 T1 IQ measured at age 1
IQ_age2_T1 T1 IQ measured at age 2
IQ_age3_T1 T1 IQ measured at age 3
IQ_age4_T1 T1 IQ measured at age 4
IQ_age1_T2 T2 IQ measured at age 1
IQ_age2_T2 T2 IQ measured at age 2
IQ_age3_T2 T2 IQ measured at age 3
IQ_age4_T2 T2 IQ measured at age 4
References
Boomsma, D. I., Martin, N. G., & Molenaar, P. C. (1989). Factor and simplex models for repeated measures: application to two psychomotor measures of alcohol sensitivity in twins. *Behavior Genetics*, **19**, 79-96. Retrieved from <https://www.ncbi.nlm.nih.gov/pubmed/2712815>
See Also
[umxSimplex()]
Other datasets:
Fischbein_wt
,
GFF
,
docData
,
umx
,
us_skinfold_data
Examples
## Not run:
data(iqdat)
str(iqdat)
par(mfrow = c(1, 3)) # 1 rows and 3 columns
plot(IQ_age4_T1 ~ IQ_age4_T2, ylim = c(50, 150), data = subset(iqdat, zygosity == "MZ"))
plot(IQ_age4_T1 ~ IQ_age4_T2, ylim = c(50, 150), data = subset(iqdat, zygosity == "DZ"))
plot(IQ_age1_T1 ~ IQ_age4_T2, data = subset(iqdat, zygosity == "MZ"))
par(mfrow = c(1, 1)) # back to as it was
## End(Not run)