What is the impact of social science and psychological science in determining what is in the best interests of a child?

In Walker v. Maxwell, 2014 BCSC 2357, aff'd at 2015 BCCA 282, I observed at para. 63: Determining what may be in the best interests of a child is sometimes obvious (e.g. protection from violence or abuse), but often entails a more nuanced, contextual analysis and one perhaps vulnerable to "common sense" assumptions informed by stereotype, popular but not necessarily accurate social science, and even myth. This may be particularly true respecting perceptions of "good parenting" and "bad parenting" and the roles of parents as a central variable and major predictor of child outcomes. There can be diverse and opposing views, often strongly held, on such matters, which is why the court often prefers for evidence respecting the unique development needs of ... children and social/ psychological science to be presented through expert witnesses who can be cross-examined as to the value and weight to be given to the research and opinions in question.