Kinship studies have shown that most cognitive ability variances are attributable to genotypic variance. Additionally, kinship correlations are generally increased when tasks that are highly g loaded are considered, a result known as the "Jensen effect". Alternatively, some studies have suggested socioeconomic status as an important factor for explaining differences in cognition. The present study investigated these premises in a sample of 141 mothers (mean age = 36.6; SD = 6.0) and their offspring (53.2% girls; mean age = 11.0; SD = 2.1). The Standard Progressive Matrices of Raven (mothers and offspring) and six other cognitive measures (offspring only) were administered. The findings suggested evidence of g heritability (Jensen effect), which is consistent with published literature on intelligence. However, kinship correlation coefficients were lower (.041 to .177) when compared to other published findings. Finally, the difference between the mother's IQ score and that of her child was influenced by SES and mother's education level.