The Benighted Expert: Professional Literature in Court
Originally published for: New York Law Journal By: Timothy M. Tippins From questions of property values in equitable distribution litigation to the psychological issues in custody cases, the domestic relations courts are awash in expertise, both real and contrived. It falls to the trial advocate to present the information that the court needs so that it can distinguish reliable testimony from the ersatz expertise that too often slithers into the courtroom. One long-entrenched method of doing so is impeachment by treatise1 which consists of confronting the witness with published writings of respected figures in the field that contradict the expert's testimony in some respect. Perhaps because this technique has been around for so long it tends to eclipse the broader importance of professional literature in measuring both the admissibility of and the weight to be accorded to an expert's testimony. This article will examine the central position that professional literature occupies in the psychology expert's world and its crucial evidentiary role in providing the very basis underlying expert opinions.
Impeachment by TreatiseThe impeachment by treatise rule allows the cross-examiner to confront the expert witness with writings of other experts that purportedly contradict the position of the expert on the stand. Before being allowed to do so, however, the cross-examiner must first lay the required foundation by extracting from the witness a concession that either (1) the expert relied upon the work at hand or (2) the texts at hand are "recognized by the profession as standard authorities."2 This foundational requirement, of course, empowers the witness to frustrate the cross-examination simply by refusing to concede that the writing is authoritative. This power can be and is abused. Experts at times tender absurd denials of the standing of a respected work to evade proper exploration of their positions. Indeed, books written to assist the expert through the courtroom thicket sometimes suggest that the expert should rarely if ever concede the authoritative status of any text.3 Taken literally this would be equivalent to an evidence professor denying that Wigmore on Evidence is an authority in the field. Some experts follow this course of action to a fault. One "expert" in infectious disease apotheosized this artifice when he testified "that he did not consider any books or articles in the field of infectious diseases 'authoritative.'"4 Absorb that statement for a moment. It is tantamount to proclaiming, "I don't hold with no book-learnin'." It demands, of course, the next question: If not from the authoritative literature of the field, then from what source did this expert acquire his or her expertise? Very recently a decision was reported wherein an expert, when asked from what source he derived the methodology that provided the underlying basis of his opinion, answered: from "my head."5 Leaving aside for the moment the possibility that he was confused as to which anatomical hollow was the true cradle of his expertise, the question such an answer irresistibly invites is how the expert knowledge arrived in his cranial cavity in the first place.
The Basis of ExpertiseTo appreciate fully the incongruity of such flippant answers, one must consider them in the context of established evidence doctrine. Except in those relatively rare instances where the expert is testifying entirely on the basis of his or her own research, the expertise which he or she purports to bring to court necessarily depends upon the professional literature of the field. Recognition of this fundamental point is precisely why the law tolerates a hearsay basis with respect to the expert's knowledge of the field. As the celebrated John Henry Wigmore wrote a century ago:
It would be absurd to deny judicial standing to such knowledge, because all scientific data must be handed down from generation to generation by hearsay, and each student can hope to test only a trifling fraction of scientific truth by personal experience.6Thus, if the expert's contention that there are no authoritative writings in his field were true, it would be time for him to depart the courtroom without another word spoken. While some species of expertise can be acquired by experience alone, e.g., an antiques dealer who testifies to value based on decades of first-hand market transactions, others depend upon formal education, degrees, board certifications and the like. Psychology falls into this latter category.
A Scientific DisciplinePsychology defines itself as a scientific discipline. Every Psychology 101 textbook will contain a statement such as: "Psychology is the science of behavior and mental processes."7 Consequently, to qualify as an expert in psychology one is required to have adequate formal credentials in this scientific field and, once so qualified, is expected to base his conclusions on the scientific knowledge of that discipline. That the expert must predicate his conclusions on the collective knowledge of his discipline is axiomatic. It was acknowledged by the U.S. Supreme Court in its landmark decision in Daubert v. Merrill Dow Pharmaceuticals.
Unlike an ordinary witness, an expert is permitted wide latitude to offer opinions, including those that are not based on firsthand knowledge or observation. Presumably, this relaxation of the usual requirement of firsthand knowledge…is premised on an assumption that the expert's opinion will have a reliable basis in the knowledge and experience of his discipline.8Reliance upon the collective knowledge of the discipline, i.e., the professional literature, is the sine qua non of expert opinion formulation. It is precisely this that distinguishes an admissible expert opinion from an inadmissible personal opinion. This most fundamental of principles is recognized within the field of forensic psychology:
The defining attributes of an expert opinion relate…to the procedures that were employed in formulating the opinion and the body of knowledge that forms the foundation upon which those procedures were developed. If the accumulated knowledge of the expert's field was not utilized, the opinion expressed is not an expert opinion. It is a personal opinion, albeit one being expressed by an expert.9Given that most custody evaluators do not conduct their own research they must necessarily rely upon the studies of others as reported in the professional literature. Therefore, it is against this professional knowledge base that the validity of their testimony must be measured. If the witness has based an opinion on neither first-hand research nor the professional literature of the discipline, the opinion ought to be rejected. Suppose, for example, that a custody evaluator observes that one of the parents exhibited behaviors "A," "B" and "C" and from these data-points concludes that the parent suffers from depression. The initial crucial question is whether that conclusion is supported by the empirical research reported in the professional literature.10 If only some idiosyncratically crafted paradigm of the individual witness supports his conclusion, what is at hand is an inadmissible personal opinion, not an expert conclusion. Such idiosyncratic assumptions or methodologies, not having been tested in the field and lacking general acceptance, should not even survive a Frye11 challenge. Even if the threshold issue of admissibility is ignored such an opinion ought to be given no weight. The critical question, therefore, is to what extent are the expert's conclusions supported by the literature? Perhaps even more fundamentally, to what extent is the witness even familiar with the published writings of the field? The trial lawyer will likely find these lines of inquiry fruitful. Reported research suggests that relatively few experts consider the literature in their practices. In one study, 27 percent of clinicians interviewed stated that "no empirical study had affected their work" and not a single "psychologist was able to identify a specific study or a specific instance of research use."12 Given psychology's self-declared status as a science, such a cavalier disregard of the expert knowledge base is nothing short of astonishing.
Custody EvaluatorsThe professional literature occupies a central position in the proper conduct of a custody assessment. The ethical and practice standards of the mental health profession require custody evaluators to keep current with and to use scientific knowledge in carrying out their forensic assignments. The American Psychological Association's (APA) Ethical Principles and Code of Conduct state:
Psychologists' work is based upon established scientific and professional knowledge of the discipline.13The APA Guidelines for Child Custody Evaluations state:
Although psychologists take care to acquire sufficient knowledge, skill, experience, training, and education prior to conducting a child custody evaluation, this acquisition is never complete. An evolving and up-to-date understanding of child and family development, child and family psychopathology, the impact of relationship dissolution on children, and the specialized child custody literature is critical to sustaining competent practice in this area.14Likewise the Association of Family and Conciliation Courts' Model Standards of Practice for Child Custody Evaluation instruct that:
A child custody evaluator shall have specialized knowledge and training in topics related to child custody work and shall keep abreast of the ever evolving research in the field.15Clearly, the profession itself recognizes that the scientific literature is the touchstone for the formulation of psychological conclusions. Thus, to properly assess the expert's conclusions, one must look to the published writings. Significantly, what is not there is as important as that which is because the burden rests upon the expert to offer up the empirical research that reflects general acceptance in the scientific community of the principles or methods upon which each inference rests.16 Such burden placement is consistent with scientific practice:
A basic tenet of science is that the burden of proof always falls squarely on the claimant, not the critic. Consequently, it is up to the proponents of these techniques to demonstrate that they work, not up to the critics of these techniques to demonstrate the converse.17In other words if the evaluator searches the professional library and, like Mother Hubbard, finds the cupboard bare, then he or she should not opine at all on the particular issue. To disregard the absence of scientific knowledge or to ignore contrary research runs afoul of the ethical and practice standards of the profession and results in the presentation of shoddy, unreliable work-product.