In my previous blog post, A Solution to Assessing Parental Capacity, I describe how the most basic and fundamental principle in developing an assessment procedure for any construct is to first define the construct (which is called its “operational definition” for assessment purposes).
This is absolutely Assessment 101 – basic and foundational.
First, operationally define the construct.
For the construct of intelligence, Spearman proposed a two-factor definition of intelligence involving an overarching form of intellectual ability – a general intelligence factor which he called g – along with specific individual factors which he callled s, such as Vocabulary, Reading Comprehension, Arithmetic Reasoning, and Computation, .
Thurstone, on the other hand, rejected Spearman’s proposal of a general factor (g) and instead proposed a multi-factor theory. Thurstone analyzed scores from 56 different tests taken by children of different ages, from which he identified seven “primary mental abilities” that include; 1) Numerical Ability, 2) Verbal Comprehension Ability, 3) Word Fluency Ability, 4) Memory Ability, 5) Reasoning Ability, 6) Spatial Ability, and 7) Perceptual Speed.
Raymond Cattell and John Horn proposed a two-factor model for intelligence comprised of Fluid intelligence (the ability to solve problems and adapt to new situations) and Crystallized intelligence (acquired knowledge through education and personal experience).
Sternberg proposed a Triarchic theory of intelligence comprised of three aspects, Analytic intelligence which is the ability to perform academic problem-solving tasks, Creative intelligence which is the ability to respond effectively to novel situations by finding new solutions to problems, and Practical intelligence which is the ability to solve real-life problems as they arise.
Alternatively, Howard Gardner (different Gardner) proposed a theory of Multiple Intelligence that includes eight different types of intelligence; 1) Linguistic Intelligence, 2) Logical/Mathematical Intelligence, 3) Spatial Intelligence, 4) Bodily/Kinesthetic Intelligence, 5) Musical/Rhythmic Intelligence, 6) Interpersonal Intelligence, 7) Intrapersonal Intelligence, and 8) Naturalistic Intelligence.
Look how much effort has been put into the assessment of children’s intellectual development, their “intelligence,” because the assessment of children’s intellectual development and the recommendations that result from the assessment can have such profound effects on the lives of children.
Child custody decisions can have equally profound effects on the lives of children. Yet no effort has been employed by professional psychology to define the construct of “best interests of the child” which is central to the child custody evaluation. This absence of professional rigor is unconscionable.
Each of the differing definitions of intelligence will produce a different method for assessing “intelligence.”
What’s more, the process of first defining the construct of intelligence promotes vigorous professional dialogue which enhances our understanding for the core meaning of the construct. Vigorous professional debate surrounding the definition of the construct greatly improves our ability to assess the construct.
But all of this valuable professional debate is absent surrounding the construct of “best interests of the child” as applied in child custody evaluations. There is no established operational definition for what the construct of “best interests of the child” means in the context of child custody evaluations.
The absence of an established definition of this fundamental construct in child custody evaluations is described by Stahl and Simons,
“A critical subject facing those working in the field of family law, whether they’re legal professionals or psychological professionals, is the concept of the best interests of the children. Even recognized experts in this concept differ with regard to what it means, how it should be determined, and what factors should be considered in determining what is in the best interest of a child. Thus, this ubiquitous term escapes consensus and remains fundamentally vague.” (Stahl & Simon, 2013, p. 10-11)
“It is defined differently from state to state; and even in Arizona, where there are nine statutory factors associated with the best interest of the child, the meaning behind many of the factors is obscure. Additionally, when psychologists refer to the best interests of children, they are referring to a hierarchical set of factors that may have different meanings to different children with different families and that may be understood differently by psychologists with different backgrounds and different training.” (Stahl & Simon, 2013, p. 11)
Stahl, P.M. and Simon, R.A. (2013). Forensic Psychology Consultation in Child Custody Litigation: A Handbook for Work Product Review, Case Preparation, and Expert Testimony, Chicago, IL: Section of Family Law of the American Bar Association
And yet, despite this violation of a fundamental and incredibly basic principle of psychological assessment – to first operationally define the construct to be assessed – the scientifically unsupported (but financially lucrative) practice of child custody evaluations continues.
Determining Best Interests
So how should we define the best interests of the child relative to various custody time-share alternatives?
Answer: There is no information in the research or theoretical literature that would allow professional psychology to develop or render an opinion regarding this question. None.
I know the child development literature. I know the clinical psychology literature. I know the research literature surrounding children, families, and divorce. There is no information in the research or theoretical literature that would allow professional psychology to develop or render an opinion regarding this question. None.
The best professional psychology can do is to identify child abuse, in which case a child protection response of 100% – 0% custody time-share is warranted for as long as the abuse potential exists. But short of child abuse, there is no information in the research or theoretical literature of professional psychology that would allow professional psychology to develop or render an opinion regarding various custody time-share options relative to the “best interests” of the child.
There is no information in the research or theoretical literature of professional psychology that would allow professional psychology to provide an opinion that a 60-40% custody time-share will be in the long-term best interests of the child over a 70-30% custody time-share, or a 50-50% custody time-share. These gradations are far too fine – exceedingly too fine – and far surpass our research and theoretical knowledge.
Define “best interest of the child” for me in a way that this definition can be applied to the variety and complexity of parent-child and family relationships (across cultural contexts). You will immediately begin to see the immense (and unsolvable) problem posed by even attempting this definition.
Short of determining the presence of child abuse in which a child protection response is warranted, professional psychology should avoid being drawn into a spousal dispute to determine who is the “better parent” and who is to be “awarded the prize” of the child for being the “better parent.” Becoming the arbiter in a spousal dispute as to who is the “better parent” to be “awarded the prize of the child” following divorce is an inappropriate professional role for professional psychology.
If there is a problem in family relationships, psychotherapy can fix the problem. But determining who is the 60% better parent relative to the other parent’s 40% good parenting, or who is the 70% better parent relative to the other parent’s 30% good parenting is not an appropriate role (and is actually an impossible role) for professional psychology to undertake.
If a custody evaluator decides that the child’s “best interests” are better served by an 80% custody time-share with the supposedly “better” parent (based on some yet undefined criteria for determining the “better” parent), how does the custody evaluator know this? Where is the research literature that supports this decision regarding the long-term best interests of the child (based on some as yet undefined criteria for determining the long-term “best interests” of the child)? Where is the research literature that indicates that the child’s long-term “best interests” are better served by being placed 80% of the time with the parenting practices of the “better” parent and that limiting the child’s contact and relationship with other parent to only 20% of the time is in the long-term “best interests” of the child? Where is the scientific evidence to support this? There is none.
There are simply too many complexities to this question that it far-far surpasses even the hope of an answer from the research base and theoretical literature of professional psychology.
There is absolutely no way – no way – professional psychology can come up with any opinion regarding the long-term benefits or impairments to a child from a 60-40% custody time-share, versus a 70-30% custody time-share, versus a 50-50% custody time-share in a specific individual family context. Rendering such an opinion far exceeds the extent and capacity of our knowledge.
It’s analogous to asking a Neanderthal to design and build a computer. The Neanderthal doesn’t even have electricity yet. The Neanderthal is chipping spear points out of stone and making fire with sticks. There is absolutely no way the Neanderthal can design and build a computer.
There are simply too many complexities (way-way too many) and too many variable factors (way too many), and our knowledge base is way too limited, to even get close to answering the question of whether a 60-40% custody time-share is in the long-term best interests of a specific child rather than a 70-30% custody time-share, or a 50-50% custody time-share. It is just complete speculation. Not even educated speculation. Just pull it out of the sky pure unadulterated guesswork.
Might as well have a monkey throw darts at a dartboard. Seriously.
Disagree? There’s a Comment section on this blog. Feel free to define for me the construct of “best interest of the child” in a way that can be applied to all the various complexities of parent-child and family relationships, and THEN cite for me any research whatsoever that would allow us to apply this definition of the “best interests of the child” to such a fine-grained discrimination as a 60-40% custody time-share versus a 70-30% custody time-share versus a 50-50% custody time-share, and that describes what parenting factors in all of the complexity of parent-child and family relationships (across cultures) would allow for such fine-grained custody time-share decisions relative to the proposed definition for the “best interests of the child.”
Impossible. Impossible. Impossible.
So why isn’t the impossibility of this exposed? Because everyone in professional psychology is pretending that they see the emperor’s beautiful new clothing.
The emperor has no clothes. The emperor is naked.
Once professional psychology lives up to its own established standards of practice regarding the development of “assessment techniques” (Standard 9.05 of the APA ethics code), or is forced to live up to these standards by the Court, so that an operational definition for the construct of “best interests of the child” becomes required of the professional assessment practice, then the entire house of cards surrounding the biased and unscientific practice of child custody evaluations will collapse.
Standard 9.05 of the APA ethics code regarding the construction of “assessment techniques” requires:
9.05 Test Construction
Psychologists who develop tests and other assessment techniques use appropriate psychometric procedures and current scientific or professional knowledge for test design, standardization, validation, reduction or elimination of bias and recommendations for use.
“…and other assessment techniques…” – like child custody evaluations.
And “standardization” refers not just to standardizing the procedures for data collection, standardization also refers to standardizing the interpretation of the collected data. If two different evaluators can interpret the data differently based on the fact that the best interests of the child “may be understood differently by psychologists with different backgrounds and different training” (Stahl & Simon, 2013), then the interpretation of the data is not standardized.
Vigorous Professional Debate
For the life of me, I cannot come up with a cogent definition for the “best interests of the child” based on “current scientific or professional knowledge” – it’s like asking this poor Neanderthal to design and build a computer. I can’t fathom how to accomplish the impossible task of defining the “best interests of the child” for the astounding complexity of the various parent-child and family relationship factors involved.
But if the practice of child custody evaluations is not to be replaced by a monkey throwing darts at a dartboard, it is incumbent upon the advocates for the practice of child custody evaluations to operationally define the construct of “best interests of the child” (like Spearman, and Thorndike, and Cattell, and so many others did relative to the construct of intelligence) in order to afford professional psychology the opportunity for the vigorous professional dialogue commensurate with the astounding importance of making custody decisions that will have such a profound impact on the child and family.
The methodology for child custody evaluations that is then created as a product of this vigorous and healthy debate within professional psychology should then be subjected to the rigors of inter-rater reliability, validity (construct validity; content validity; predictive validity; convergent validity; divergent validity), and cross-cultural validation that represents the “appropriate psychometric procedures… for test design, standardization, validation, [and] reduction or elimination of bias” referenced by APA Standard 9.05 of the Ethical Principles of Psychologists and Code of Conduct.
Until this is accomplished, there exists NO INFORMATION in the professional literature or research base that would allow professional psychology to answer the question regarding the “best interests of the child” relative to alternative custody time-share options (with the exception of determining child abuse that warrants child protection considerations; leading to a 100% – 0% custody recommendation for the duration of child protection concerns).
The Solution
Children’s emotional and psychological development benefits from a complex relationship with both parents. The complexity of the parent-child relationship and the complexity of the relationship processes involved in healthy child development preclude the formation of any informed opinion or recommendation regarding the potential “best interests” of the child resulting from various custody time-share alternatives (with the exception of child abuse and child protection considerations; 100% – 0%) for specific individual family circumstances.
As a consequence of professional psychology’s inability to form or render a cogent, reliable, and demonstrably valid opinion regarding the “best interests of the child” that will result from various custody time-share options (with the exception of child abuse and child protection considerations; 100% – 0%), the custody recommendation from professional psychology for all cases that don’t involve child abuse and child protection considerations should be for a 50-50% time-share based on the principle that children benefit from complex relationships with both parents.
In the absence of child protection considerations, there is no scientifically or theoretically supported foundation for any other decision or opinion from professional psychology regarding a fine-grained discrimination in the child’s long-term “best interests” resulting from a 60-40%, 70-30%, 80-20%, or 90-10% custody time-share in specific individual family circumstances following divorce.
Professional psychology should avoid being drawn into spousal conflicts surrounding divorce to render an opinion as to who is the “better parent” to be “awarded the prize” of the child following divorce.
If the parents wish to work out some alternative custody time-share arrangement, that is their right and that is their prerogative.
But if professional psychology is asked for an opinion, the only rational and supported opinion which can be offered by professional psychology given the immense complexity surrounding parent-child and family relationships (including the cultural context of parenting and family relationship structures) regarding various custody time-share alternatives is for 50-50% custody timeshare equally with both parents (with the exception of child abuse and child protection considerations; 100% – 0%) based on the principle that children benefit from complex relationships with both parents.
If family problems exist with a 50-50% custody time-share, this represents a family therapy issue, not a custody-related issue. The family problems should be assessed and a treatment plan can be developed to resolve the family problems. This is not a custody-related issue. This is a treatment issue.
Craig Childress, Psy.D.
Clinical Psychologist, PSY 18857



