The Theory of Parental Investment predicts a decrement in parental investment as the benefit/cost ratio decreases. Differences in maternal investment were investigated in relation to socio-environmental variables that may have an impact on the benefit/cost ratio. The factors investigated showed, in general, effects on maternal investment in the expected direction according to the theory: as costs increased, represented by the absence of cohabitation with the father, diminished income and early reproductive age, lower levels of investment were observed. It is concluded that socio-environmental factors may promote or inhibit maternal investment, indicating the importance of public policies in promoting the stability of these variables.
parental investment; maternal care; socio-environmental variables; reproductive history
