Mathematical Aptitude and Family Income in North-Eastern Tribes

Aptitude test scores have applications in predicting success of students on future career, appropriate choice of subjects in higher studies, etc. Scholastic Aptitude Test (SAT) scores are known to be positively associated with family income. SAT has mathematical aptitude as one of the test components. It is of interest to investigate for possible relationship of mathematical aptitude and family income among the tribals in Northeast India for proper choice in career selection. We study mathematical aptitude and its relationship with family income among North-eastern tribal students on several occasions. The cross-sectional survey is conducted relatively recently within the time range of about 6 months during 6 March 2017 to 2 September 2017 in Agartala, Tripura, after a region-wise stratification of academic institutions at the first stage. The students are then selected by simple random sampling from different academic institutions on several time points. In the lowest rung of economic condition with poor monthly income, the aptitude scores are seen to be low. A slowly increasing trend in scores is seen with family income by nonparametric LOWESS regression, especially towards higher-income groups. Association of variables by Spearman rank correlation and Kendal’s $$\tau $$ indicate little or no relationship of income and aptitude scores, in contrast to LOWESS growth curve. Correlation between LOWESS predicted score and log (family income) is 0.7635 among data from 154 students, indicating a positive association of the variables. Intra-class correlation in collected data indicates lack of cohesion in aptitude scores within groups, and the same holds for the aggregate of all students over five groups in the conducted survey, implying that the scores do not resemble much with each other.