Merriam Webster defines a rule of thumb as: (1) a method of procedure based on experience and common sense; (2) a general principle regarded as roughly correct but not intended to be scientifically accurate.
In deciding child custody cases, the “best interests” doctrine has been with us from time in memorial and with good reason. A legion of reported decisions cite this standard, which gives a court broad discretion to look at the totality of the circumstances to determine what is in a child’s best interests when adjudicating a custody dispute.
Determining Factors
Factors utilized by a court in determining best interests include, but are not limited to: each parent's relative fitness, including his or her ability to guide the child, provide for the child's overall well-being, and provide for the child's emotional and intellectual development; the effect an award of custody to one parent might have on the child's relationship with the other parent; which alternative will best promote stability; each parent’s ability to provide for the child financially; the available home environments; the past performance of each parent; and each parent’s relative fitness.
Despite the multitude of factors and considerations that comprise the best interests doctrine, the current (and, potentially, dangerous) matrimonial zeitgeist is to sometimes favor a “rule of thumb” approach rather than a true best interests analysis.
Examples of ‘Rule of Thumb’
Perhaps the most common (and striking) examples of a “rule of thumb” are that parents are each entitled to 50/50 parenting time or that a parent gets no less than X% of the parenting time (despite there being no legal presumption for either). Another “rule of thumb” espoused is that children are “resilient” (when some children are not, or less so than other children).
It is dangerous to apply rules of thumb to custody disputes because we run the risk of creating a de facto rebuttable presumption that the rule of thumb is law. It is not.
Perhaps more importantly, by applying rules of thumb which are, by definition, generalizations based upon “experience” and “common sense,” and which are not intended to be “scientifically accurate,” we risk losing site of what the best interests of the child means under the law.
One can and should argue the factors that the court should consider as well as how much weight a court should apply to any one or more factors. However, for best interests of the child to be meaningful, best interests must be defined as no less than the best interests of this child, not the hypothetical child to which a generalized rule of thumb might be applied.
If it is the best interests of this child that must be determined, then, logically, applying a rule of thumb of a hypothetical child(ren) could never be what is in a particular child’s best interests.
"Child Custody: The Dangers of 'Rules of Thumb,'" by Dylan S. Mitchell was published in the New York Law Journal on January 30, 2025.
Reprinted with permission from the January 30, 2025, edition of the New York Law Journal © 2025 ALM Media Properties, LLC. All rights reserved. Further duplication without permission is prohibited.
