In spite of enjoying a higher level of female autonomy in a strong matrilineal kinship system, women in matrilineal societies in northeast India have the highest fertility in the country. This direct association of high female autonomy and high fertility challenges the most commonly observed inverse relationship between these two variables in other populations. Preliminary findings from a comparative analysis of the Khasis and the Karbis - two tribal communities with two different kinship systems, highlight the fact that in traditional tribal societies decisions regarding reproduction are not only influenced by individual level factors. Instead, this paper argues that the perceptions and the behaviour related to reproduction are strongly, even predominantly, determined by prevailing cultural and religious values, that form the basis of socially-sanctioned realities in these communities. It is also argued that reproductive behaviour in these communities is strongly influenced by the insecurities associated with minority-group status. This paper highlights the reality of reproductive norms among these tribal groups and hypothesizes that the perception of minority status and the adoption of a more defensive position vis-à-vis outside groups has impacted on fertility outcomes in these communities. This phenomenon calls for further development and refinement of India’s National Population Policy.