Allocations of child custody post-divorce are currently determined according to the Best Interest Standard, i.e. what is best for the child. Decisions about what is best for a child necessarily reflect cultural norms, at least in part. It is therefore useful as well as interesting to ask whether current understandings of the best interest standard align with moral intuitions of lay citizens asked to take the role of judge in hypothetical cases. Do factors such as whether one parent had an extramarital affair influence how respondents would award custody? In the current studies, a representative sample of citizens awaiting jury service was first given a neutral scenario portraying an "average" family. Almost 80% favored dividing custodial time equally between the two parents, replicating earlier findings. Then, in Study 1, they were given a second, Test case, vignette in which either the mother or the father was said to have carried on an extramarital affair that "essentially ruined the marriage". In Study 2, either the mother or the father was said to have sought the divorce, opposed by the other, simply because he or she "grew tired" of the marriage. For both Test cases, our respondents awarded the offending parent significantly less parenting time; about half of our respondents in each Study. The findings indicate that many citizens feel both having an affair and growing tired of the marriage is sufficient cause to award decreased parenting time, reasons for which are explored in the discussion. Between 40 and 50 percent of marriages end in divorce (Cherlin, 2010). These divorces obviously affect children, although such effects vary in their magnitude, nature, and causal pathways (Amato, 2005;Bhrolchain, et al, 2000;Bhrolchain, 2001;Braver & Lamb, 2012Hetherington & Kelly, 2002;Lamb, 2012;Potter, 2010). Parental conflict, troubled parent-child relationships, and wholesale changes to their lives are risk factors for social, psychological, and educational difficulties in children, and are all associated with family breakdown (although whether divorce per se is the causative agent is more debatable, since these stressors often precede divorce; Chase-Lansdale, Cherlin, & Kiernan, 1995;Cherlin, Furstenberg, Chase-Lansdale, Kiernan, Robins, Morrison, & Teitler, 1991). Recent decades have seen renewed interest in strategies to reduce the risks associated with family breakdown.One possible lever is ensuring custodial arrangements that increase the prospects of the child retaining a healthy and supportive relationship with both parents (Amato, 2005;.Family law, including custody law, is inevitably affected by prevailing cultural values, possibly even more so than for many other areas of law. This influence can be demonstrated by examining the historical contexts during which shifts in the law occurred. Prior to around the second half of the nineteenth century, English family law was primarily concerned with the preservation of family estates, passed down through generations via the primogeniture rule favoring t...