Objective. To analyze and compare the heights of first-year school children
and their parents, according to: ethnic background and socioeconomic statu
s. Material and methods. This is a cross-sectional study of indigenous and
non-indigenous school children and their parents, belonging to three levels
of social vulnerability: very high (poverty), medium, and very low. An ind
igenous school child was defined as any child having all four parental surn
ames of Mapuche origin; non-indigenous were those having Hispanic parental
surname. Height: was compared using Z scores, using;WHO nutritional change
reference values. Statistical analysis consisted in comparing differences o
f mean heights between parents and their children. Differences were assesse
d using Scheffe's method. Results. Improvement in socioeconomic conditions
was associated with increasing mean parental height (p<0.001), except for i
ndigenous mothers, who showed no height increase. Fathers from highly impov
erished counties were 4 cm shorter than those living in very low vulnerabil
ity areas; height differences reached 2 cm among mothers (p<0.001). Indigen
ous school children showed a positive height gradient with improving socioe
conomic conditions (p<0.001). This was not observed among non-indigenous ch
ildren. When comparing parental height with children's height, children had
a better height/age ratio than their parents (p<0.01). This was specially
evident among indigenous school children,who had on average 1.4 Z scores mo
re than their parents. Conclusions. The upward height gradient related to i
mproved social conditions, and the better height/age ratio seen in children
in comparison to their parents, regardless their ethnic background and lev
el of social vulnerability, is encouraging and suggests that interventions
directed to the poorest groups, including the indigenous population, must b
e carried out.