The urban population as compared with the rural shows some rather striking difference in age, the percentage 20 to 44 years of age being 40.6 for the urban population as compared with 36.2 for the rural, while the percentage under 15 years is 30.4 the urban population as against 37.2 in the rural. These differences may indicate larger families of children in the country than in the city, but probably indicate also the fact that country children as they grow up have a tendency to flock to the cities thereby increasing the active adult population of the cities at the expenses of the rural districts.

A little over one-half of the population, 54.2 percent are old enough to vote, being 21 or over; and in this class the men outnumber the women in the ratio of 131 to 100. The males of military or fighting age, 18 to 44, constitute 40.9 percent of the male population and 22.2 percent of the total population.

According to the census of 1920, there are 4,924 illiterate persons 10 years of age and over in the state of Idaho, "illiterate" meaning unable to write. Of this number 913 are native whites and 2,601 are foreign born. In the total population 10 years of age and over the percentage of illiteracy is 1.5, which shows a diminution since 1910, when it was 2.2. 