Theory testing, effect-size evaluation, and differential susceptibility to rearing influence: the case of mothering and attachment.

It is important to distinguish theory testing from effect-size evaluation when considering the impact of mothering on attachment security discerned in the De Wolff and van Ijzendoorn meta-analysis. Moreover, the possibility exists that this analysis both over- and underestimates mothering effects, as would be the case if infants vary in their susceptibility to rearing influence.