The database of heights (N = 16.266) is composed of conscripts who reached the age of 21 between 1908 and 1985 (birth cohorts 1886-1965). The population sample has been taken from a municipality in inner Spain: Hellín, in the region of Castilla-La Mancha, mainly an agrarian area, with poor resources and low income until the 1970 s/1980 s. Two different methodologies have been implemented: a harmonic regression using sinusoidal covariables and a random forest model.
we find that being born at the end of the summer and during the autumn was favorable to height. The birth month with the highest statures is September, with heights 0.5 cm above the annual average and 0.9 cm above February, the birth month with the lowest average height. Furthermore, we can observe that rainfall and temperature during gestation had little additional influence due to a substitution effect with the birth month variable.
Our results suggest that the seasonal effects on height can be significant and that it can be partially affected by environmental factors during early life. Our findings could be of interest for low-income populations and developing rural societies.
身高数据库(N=16.266)由1908年至1985年之间达到21岁的应征入伍者组成(出生队列1886-1965)。人口样本来自西班牙内陆的一个城市:海林,在卡斯蒂利亚-拉曼查地区,主要是农业区,在1970年代/1980年代之前,资源贫乏,收入低。已经实现了两种不同的方法:使用正弦协变量的调和回归和随机森林模型。
我们发现,在夏末和秋天出生有利于身高。身材最高的出生月份是九月,身高高于年平均水平0.5厘米,高于2月0.9厘米,平均身高最低的出生月份。此外,我们可以观察到,由于与出生月份变量的替代效应,妊娠期间的降雨和温度几乎没有额外的影响。
我们的结果表明,季节对身高的影响可能是显着的,并且在生命早期可能受到环境因素的部分影响。我们的发现可能对低收入人口和发展中的农村社会感兴趣。