crawl: The age at which babies start to crawl

In GLMsData: Generalized Linear Model Data Sets

The age at which babies start to crawl

Description

The age at which babies start to crawl, the birth month and average monthly temperature six months after the birth month

Usage

data(crawl)

Format

A data frame with 12 observations on the following 5 variables.

BirthMonth

the baby's birth month; levels such as January and July

Age

the mean age (in completed weeks) at which the babies born this month started to crawl; a numeric vector

SD

the standard deviation (in completed weeks) of the crawling ages for babies born this month; a numeric vector

SampleSize

the number of babies in the study born in the given month; a numeric vector

Temp

the monthly average temperature (in degrees F) six months after the birth month; a numeric vector

Details

The data come from a study which hypothesized that babies would take longer to learn to crawl in colder months because the extra clothing restricts their movement. From 1988–1991, recorded were the babies' first crawling age and the average monthly temperature 6 months after birth (when “infants presumably enter the window of locomotor readiness”). The parents reported the birth month, and age when their baby first crept or crawled a distance of four feet in one minute. Data were collected at the University of Denver Infant Study Center on 208 boys and 206 girls, and summarized by the birth month.

Source

Janette Benson (1993) Season of birth and onset of locomotion: Theoretical and methodological implications. Infant Behavior and Development, 16(1), 69–81.

Thanks to Janette Benson for granting permission to use this data set.

Examples

data(crawl)
plot(Age ~ Temp, data=crawl, cex=0.05*SampleSize, pch=19)

GLMsData documentation built on Aug. 22, 2022, 9:10 a.m.