Biography
William V. Fabricius received his Ph.D. in Developmental Psychology from the University of Michigan. He is Associate Professor of Psychology, and an Affiliated Faculty in Law and Behavioral Science, at Arizona State University. He has been awarded research grants totaling over five million dollars from the National Institute of Mental Health, and the National Institute of Child Health and Human Development. He has published over 70 empirical research articles and scholarly chapters in peer-reviewed journals and books and given more than 40 invited presentations and consultations to family law organizations and conferences. From 2002 to 2013, he served on the Domestic Relations Committee at the Arizona State Legislature, and in that capacity he led the effort that resulted in major reforms to the Arizona child custody statutes. These laws made Arizona the first state to have a de facto rebuttable presumption that it is in childrens best interests to have equal parenting time with both parents after parental separation. In 2010, he received the Science and Research Award presented by the Arizona Chapter of the Association of Family and Conciliation Courts. In 2024 he was awarded the National Parents Organization Ned Holstein Shared Parenting Research Lifetime Achievement Award.

Plenary title
The Scientific Case for Legal Presumption of Equal Parenting Time

Abstract
I will examine the necessary components of the scientific case for legal presumptions of equal parenting time (EPT). The first component is the theoretical causal model that identifies the mechanisms by which EPT legislation benefits children. The model specifies that (a) legislation will increase rates of EPT, (b) EPT will protect children’s emotional security with both parents, and (c) children’s emotional security will have a positive effect on public health in the form of reduced long-term stress-related mental and physical health problems among children of divorce. The second component is the empirical evidence for each of the causal links. (a) is supported by evidence from Spain. (b) is supported by correlational findings that meet five conditions necessary for a causal role of EPT: A legal context that constrains the possibility of self-selection into EPT; a dose-response positive association between parenting time and emotional security with fathers; the association is maintained when courts impose more parenting time, and when relocations reduce parenting time with fathers; and the direction of the association is from changes in parenting time at one year to changes in father-child security the next year, and not vice versa, and after controlling for stable traits of fathers and children. The third component is empirical evidence that the association is maintained in families with high parental conflict, and in families with children under age three. (c) is supported by evidence of infants’ attachment to fathers, and by the voluminous public health literature. Finally, if time permits, I will discuss some strategies for not only translating the scientific evidence into policy — including getting buy-in from the anti-domestic violence community, lawyers, and judges — but also maintaining support for the legal reform by putting mechanisms in place to monitor courts’ compliance.