One cultural factor that may affect ethnic differences in educational achievement is poor linguistic skills. Berieter and Engelmann consider language spoken by low income black American families as inadequate for educational success. For example if ethnic minority students speak using the restricted code, as discussed by Bernstein, it may prevent them from understanding teachers who use the elaborated code therefore hindering their educational success.Furthermore, another cultural factor that may affect ethnic differences in educational differences is parental support. Moynihan argues that many black families are headed by lone mothers which leaves their children deprived of adequate care, since the mother struggles financially in the absence of the male breadwinner. This could cause a lack of motivation to achieve due to the lack of support and encouragement from their mothers.