In this respect, Waller et al. (2016), using an adoption sample as well as longitudinal measures (
fearlessness was measured at 18 months, CU traits and ODD at 27 months), demonstrated that biological mother's
fearlessness predicted CU traits
via earlier child
fearlessness.
In the first study [44], temperament (
fearlessness) of the biological mother predicted CU behaviour of the adopted child at 27 months,
via earlier
fearlessness measured at 18 months; similarly, low affiliative behaviour of biologic mothers directly predicted child CU behaviours, although without any correlation with child affiliative behaviours tested at 18 months.