Social Science and Parenting Plans for Young Children: A Consensus Report Richard A. Warshak University of Texas Southwestern Medical Center, with the endorsement of the researchers and practitioners listed in the Appendix Two central issues addressed in this article are the extent to which young children’s time should be spent predominantly in the care of the same parent or divided more evenly between both parents, and whether children under the age of 4 should sleep in the same home every night or spend overnights in both parents’ homes. A broad consensus of accomplished researchers and practitioners agree that, in normal circumstances, the evidence supports shared residential arrangements for children under 4 years of age whose parents live apart from each other. Because of the well-documented vulnerability of father– child relationships among never-married and divorced parents, the studies that identify overnights as a protective factor associated with increased father commitment to child rearing and reduced incidence of father drop-out, and the absence of studies that demonstrate any net risk of overnights, policymakers and decision makers should recognize that depriving young children of overnights with their fathers could compromise the quality of developing father-child relationships. Sufficient evidence does not exist to support postponing the introduction of regular and frequent involvement, including overnights, of both parents with their babies and toddlers. The theoretical and practical considerations favoring overnights for most young children are more compelling than concerns that overnights might jeopardize children’s development. Keywords: child custody, children’s best interests, joint custody, overnights, shared parenting One hundred and ten researchers and practitioners have read, provided comments, and offered revisions to this article. They endorse this article’s conclusions and recommendations, although they may not agree with every detail of the literature review. Their names and affiliations are listed in the Appendix. Social science provides a growing and sophisticated fund of knowledge about the needs of young children, the circumstances that best promote their optimal development, and the individual differences among children regarding their adaptability to different circumstances, stress, and change. Consequently, research focused on children whose parents never married, or whose parents sepa- rated or divorced, should inform guidelines to advance the welfare and define the best interests of those children; indeed, policymak- ers and practitioners in family law look to that research for such information. But the road from laboratories to legislatures and family law courtrooms is hazardous—fraught with potential for misunderstandings, skewed interpretations, logical errors, even outright misrepresentations. The hazards can be traced, in large measure, to differences between science and advocacy. Scientific approaches to a literature review aim for a balanced, accurate account of established knowledge and of unresolved issues that require further investigation. When there are discrep- ancies among findings, scientists strive to understand the reason for the discrepancies, and to assess the strength of the research designs and methods. By nature, scientific knowledge is incom- plete; thus, not all findings and conclusions are equally trustwor- thy. Hence the need for balanced, accurate reviews. Advocacy approaches are recognizable by certain core features: Advocates select literature for the purpose of promoting a particular agenda, and ignore or minimize findings that fail to support the desired conclusions; they distort findings toward the advocate’s position; and they use a variety of polemics, loose logic, and emotional appeals to build a persuasive case. With respect to critical thinking about research, Meltzoff (1998) writes the following: “Research shows” is one of the favorite expressions of psychologists who are called on by the media to express their professional opinions on a wide range of topics, who are asked to consult with or testify before lawmakers about social issues that affect public welfare, or who are relied on to give expert counsel to other health service providers or to educators. Research psychologists carry a heavy bur- den of responsibility for assuring the accuracy of their claims about their results. In turn, psychologists who cite or apply the research findings of others share their responsibility. They have an obligation to use their critical reading and evaluation skills in reviewing a study before they cite it as evidence that supports a point of view and before they apply the findings in their clinical work. (p. 9) The purposes for this document are to provide the family court system—including lawmakers, mediators, decision-makers, par- ents, guardians ad litem, child custody evaluators, and therapists– with an overview of the research on parenting plans for children under the age of four years whose parents live apart, and to provide empirically supported guidelines that reflect a consensus among Richard A. Warshak, Department of Psychiatry, Division of Psychology, University of Texas Southwestern Medical Center Dallas. I appreciate the valuable feedback to a draft provided by William V. Fabricius. Correspondence concerning this article should be addressed to Richard A. Warshak 16970 Dallas Parkway, Suite 202, Dallas, TX 75248. E-mail: doc@warshak.com This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. Psychology, Public Policy, and Law © 2014 American Psychological Association 2014, Vol. 20, No. 1, 46 – 67 1076-8971/14/$12.00 DOI: 10.1037/law0000005 46